diff --git a/tests/color.class.sh b/tests/color.class.sh
new file mode 100644
index 0000000000000000000000000000000000000000..362078205343127eac90576b64e96e9aca4cd3e9
--- /dev/null
+++ b/tests/color.class.sh
@@ -0,0 +1,601 @@
+#!/bin/bash
+# ======================================================================
+#
+# COLORS
+#
+# a few shell functions for colored output
+#
+# ----------------------------------------------------------------------
+# License: GPL 3.0
+# Source: <https://github.com/axelhahn/bash_colorfunctions>
+# Docs: <https://www.axel-hahn.de/docs/bash_colorfunctions/>
+# ----------------------------------------------------------------------
+# 2023-08-09 ahahn 0.1 initial lines
+# 2023-08-09 ahahn 0.2 hide output of regex test with grep
+# 2023-08-13 ahahn 0.3 introduce of color presets with foreground and background
+# 2023-08-13 ahahn 0.4 list presets, debug, count of colors
+# 2023-08-13 ahahn 0.5 support of RGB hex code
+# 2023-08-14 ahahn 0.6 fix setting fg and bg as RGB hex code
+# 2023-08-14 ahahn 0.7 remove color.ansi; respect NO_COLOR=1
+# 2023-08-16 ahahn 0.8 add function color.preset
+# ======================================================================
+
+_VERSION=0.8
+typeset -i COLOR_DEBUG; COLOR_DEBUG=0
+
+# ----------------------------------------------------------------------
+# CONSTANTS
+# ----------------------------------------------------------------------
+
+declare -A BGCOLOR_CODE
+declare -A COLOR_CODE
+
+# background colors
+BGCOLOR_CODE[black]="40"
+BGCOLOR_CODE[red]="41"
+BGCOLOR_CODE[green]="42"
+BGCOLOR_CODE[brown]="43"
+BGCOLOR_CODE[blue]="44"
+BGCOLOR_CODE[purple]="45"
+BGCOLOR_CODE[cyan]="46"
+BGCOLOR_CODE[lightgray]="47"
+BGCOLOR_CODE[darkgray]="1;40"
+BGCOLOR_CODE[lightred]="1;41"
+BGCOLOR_CODE[lightgreen]="1;42"
+BGCOLOR_CODE[yellow]="1;43"
+BGCOLOR_CODE[lightblue]="1;44"
+BGCOLOR_CODE[lightpurple]="1;45"
+BGCOLOR_CODE[lightcyan]="1;46"
+BGCOLOR_CODE[white]="1;47"
+
+# foreground colors
+COLOR_CODE[black]="30"
+COLOR_CODE[red]="31"
+COLOR_CODE[green]="32"
+COLOR_CODE[brown]="33"
+COLOR_CODE[blue]="34"
+COLOR_CODE[purple]="35"
+COLOR_CODE[cyan]="36"
+COLOR_CODE[lightgray]="37"
+COLOR_CODE[darkgray]="1;30"
+COLOR_CODE[lightred]="1;31"
+COLOR_CODE[lightgreen]="1;32"
+COLOR_CODE[yellow]="1;33"
+COLOR_CODE[lightblue]="1;34"
+COLOR_CODE[lightpurple]="1;35"
+COLOR_CODE[lightcyan]="1;36"
+COLOR_CODE[white]="1;37"
+
+# custom presets as array of foreground and background color
+#
+# +--- the label is part of the variable
+# |
+# v
+# COLOR_PRESET_error=("white" "red")
+# COLOR_PRESET_ok=("white" "green")
+
+# ----------------------------------------------------------------------
+# PRIVATE FUNCTIONS
+# ----------------------------------------------------------------------
+
+# write debug output - if debugging is enabled
+# Its output is written to STDERR
+# param string text to show
+function color.__wd(){
+ test "$COLOR_DEBUG" = "1" && >&2 echo "DEBUG: $*"
+}
+
+# test, if given value is a known color name
+# param string colorname to test
+function color.__iscolorname(){
+ test -n "${COLOR_CODE[$1]}" && return 0
+ return 1
+}
+
+# test, if given value is a value 0..7
+# param string color to test
+function color.__iscolorcode(){
+ test "$1" = "0" && return 0
+ test "$1" = "1" && return 0
+ test "$1" = "2" && return 0
+ test "$1" = "3" && return 0
+ test "$1" = "4" && return 0
+ test "$1" = "5" && return 0
+ test "$1" = "6" && return 0
+ test "$1" = "7" && return 0
+ return 1
+}
+
+# test, if given value is an ansi code
+# param string color to test
+function color.__iscolorvalue(){
+ if grep -E "^([01];|)[34][0-7]$" >/dev/null <<< "$1" ; then
+ return 0
+ fi
+ return 1
+}
+
+# test, if given value is an rgb hexcode eg. #80a0f0
+# param string color to test
+function color.__isrgbhex(){
+ if grep -iE "^#[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]$" >/dev/null <<< "$1" ; then
+ return 0
+ fi
+ return 1
+}
+
+# convert rgb hex code eg. #80a0f0 to 3 decimal values
+# output us a string with space separated values for red, green, blue
+# param string color as "#RRGGBB" to convert
+function color.__getrgb(){
+ local _r
+ local _g
+ local _b
+ if color.__isrgbhex "$1"; then
+ _r=$( cut -c 2,3 <<< "$1" )
+ _g=$( cut -c 4,5 <<< "$1" )
+ _b=$( cut -c 6,7 <<< "$1" )
+ echo "$((16#$_r)) $((16#$_g)) $((16#$_b))"
+ fi
+}
+
+# test, if given value is a color that can be one of
+# - colorname
+# - value 0..7
+# - ansi code
+# param string color to test
+function color.__isacolor(){
+ if color.__iscolorname "$1"; then return 0; fi
+ if color.__iscolorcode "$1"; then return 0; fi
+ if color.__iscolorvalue "$1"; then return 0; fi
+ if color.__isrgbhex "$1"; then return 0; fi
+ color.__wd "$FUNCNAME is acolor: $1 --> No"
+ return 1
+}
+
+# test, if given value is an existing preset
+# param string color to test
+function color.__isapreset(){
+ local _colorset
+ eval "_colorset=\$COLOR_PRESET_${1}"
+ test -n "$_colorset" && return 0
+ return 1
+}
+
+# respect NO_COLOR=1
+# return 1 if colors are allowed to be used.
+function color.__usecolor(){
+ test "$NO_COLOR" = "1" && return 1
+ return 0
+}
+
+# set foreground or background
+# param string color as
+# - basic color 0..7 OR
+# - color name eg. "black" OR
+# - a valid color value eg. "1;30" OR
+# - a hex code eg. "#10404f"
+# param integer what to set; '3' for for foreground or '4' for background colors
+function color.__fgorbg(){
+ local _color="$1"
+ local _prefix="$2"
+ color.__wd "$FUNCNAME $1 $2"
+ if color.__iscolorname "${_color}"; then
+ color.__wd "yep, ${_color} is a color name."
+ test "$_prefix" = "3" && color.set "${COLOR_CODE[${_color}]}"
+ test "$_prefix" = "4" && color.set "${BGCOLOR_CODE[${_color}]}"
+ else
+ if color.__iscolorcode "${_color}"; then
+ color.__wd "yep, ${_color} is a color code."
+ else
+ if color.__iscolorvalue "${_color}"; then
+ color.__wd "yep, ${_color} is a color value."
+ color.set "${_color}"
+ else
+ if color.__isrgbhex "${_color}"; then
+ local _r
+ local _g
+ local _b
+ read -r _r _g _b <<< $( color.__getrgb "${_color}" )
+ color.set "${_prefix}8;2;$_r;$_g;$_b"
+ else
+ >&2 echo "ERROR: color '${_color}' is not a name nor a value between 0..7 nor a valid color value nor RGB."
+ fi
+ fi
+ fi
+ fi
+}
+
+# ----------------------------------------------------------------------
+# FUNCTIONS :: helpers
+# ----------------------------------------------------------------------
+
+# get count of colors in the current terminal
+function color.count(){
+ tput colors
+}
+
+# enable debug flag
+function color.debugon(){
+ COLOR_DEBUG=1
+ color.__wd "$FUNCNAME - debugging is enabled now"
+}
+
+# disable debug flag
+function color.debugoff(){
+ color.__wd "$FUNCNAME - disabling debugging now"
+ COLOR_DEBUG=0
+}
+
+# show debugging status
+function color.debugstatus(){
+ echo -n "INFO: color.debug - debugging is "
+ if [ $COLOR_DEBUG -eq 0 ]; then
+ echo "DISABLED"
+ else
+ echo "ENABLED"
+ fi
+}
+
+# show help
+function color.help(){
+ local _self; _self='[path]/color.class.sh'
+ color.reset
+ local _debug=$COLOR_DEBUG
+ COLOR_DEBUG=0
+
+ echo "_______________________________________________________________________________"
+ echo
+ color.echo "red" " ### ### # ### ####"
+ color.echo "yellow" " # # # # # # # #"
+ color.echo "white" " # # # # # # ####"
+ color.echo "yellow" " # # # # # # # #"
+ color.echo "red" " ### ### ##### ### # #"
+ echo "_________________________________________________________________________/ v$_VERSION"
+ echo
+
+ sed "s#^ ##g" << EOH
+ HELP:
+ 'color' is a class like component to simplify the handling of ansi colors and keeps
+ the color settings readable. A set NO_COLOR=1 will be respected.
+
+ Author: Axel Hahn
+ License: GNU GPL 3.0
+ Source: <https://github.com/axelhahn/bash_colorfunctions>
+ Docs: <https://www.axel-hahn.de/docs/bash_colorfunctions/>
+
+
+ FUNCTIONS:
+
+ ---------- Information:
+
+ color.help this help
+ color.list show a table with valid color names
+ color.presets show a table with defined custom presets
+
+ color.count get count of colors in the current terminal
+
+ color.debugon enable debugging
+ color.debugoff disable debugging
+ color.debugstatus show debugstatus
+
+ ---------- Colored output:
+
+ color.bg COLOR (COLOR2)
+ set a background color; a 2nd parameter is optional to set
+ a foreground color too
+ color.fg COLOR (COLOR2)
+ set a foreground color; a 2nd parameter is optional to set
+ a background color too
+ color.preset PRESET
+ Apply the color set of foreground and background of a given
+ preset name.
+ color.echo COLOR|PRESET (COLOR2) TEXT
+ write a colored text with carriage return and reset colors
+ The 1st param must be a COLOR(code/ name) for the
+ foreground or a label of a preset.
+ The 2nd CAN be a color for the background, but can be
+ skipped.
+ Everything behind is text for the output.
+ color.print COLOR|PRESET (COLOR2) TEXT
+ see color.echo - the same but without carriage return.
+ color.reset reset colors
+ color.set RAWCOLOR (RAWCOLOR2 (... RAWCOLOR_N))
+ set ansi colors; it can handle multiple color values
+
+
+ ---------- Other:
+
+ color.blink start blinking text
+ color.bold start bold text
+ color.invert start inverted text
+ color.underline start underline text
+
+ VALUES:
+ COLOR a color; it can be...
+ - a color keyword, eg black, blue, red, ... for all
+ known values run 'color.list'
+ - a value 0..7 to set basic colors 30..37 (or 40..47)
+ - an ansi color value eg. "30" or "1;42"
+ - RGB hexcode with '#' as prefix followed by 2 digit
+ hexcode for red, green and blue eg. "#10404f"
+ (like css rgb color codes)
+ PRESET Name of a custom preset; see DEFINE PRESETS below.
+ RAWCOLOR an ansi color value eg. "30" (black foreground) or
+ "1;42" (lightgreen background)
+
+
+ DEFINE PRESETS:
+ A shortcut for a combination of foreground + background color. The label
+ is part of a bash variable with the prefix 'COLOR_PRESET_'.
+ The value is a bash array with 2 colors for foreground and background.
+ See the value description for COLOR above.
+
+ SYNTAX:
+ COLOR_PRESET_<LABEL>=(<FOREGROUND> <BACKGROUND>)
+
+ To see all defined presets use 'color.presets'
+
+
+ EXAMPLES:
+ First you need to source the file $_self.
+ . $_self
+
+ (1)
+ Show output of the command 'ls -l' in blue
+ color.fg "blue"
+ ls -l
+ color.reset
+
+ (2)
+ show a red error message
+ color.echo "red" "ERROR: Something went wrong."
+
+ (3)
+ Use a custom preset:
+ COLOR_PRESET_error=("white" "red")
+ color.echo "error" "ERROR: Something went wrong."
+
+ This defines a preset named "error". "white" is a colorname
+ for the foreground color, "red" ist the background.
+
+EOH
+
+ if [ -n "$NO_COLOR" ]; then
+ echo -n "INFO: NO_COLOR=$NO_COLOR was set. The coloring functionality is "
+ if ! color.__usecolor; then
+ echo "DISBALED."
+ else
+ echo "ENABLED (must be 1 to disable)."
+ fi
+ echo
+ else
+ echo "INFO: NO_COLOR will be respected - but it is not set."
+ fi
+
+ COLOR_DEBUG=$_debug
+}
+
+# a little helper: show colors and the color codes
+function color.list(){
+ color.reset
+ local _debug=$COLOR_DEBUG
+ COLOR_DEBUG=0
+
+ echo
+ echo "List of colors:"
+ echo
+
+ echo "--------------------------------------------------"
+ echo "color | foreground | background"
+ echo "--------------------------------------------------"
+ for i in "${!COLOR_CODE[@]}"
+ do
+ printf "%-15s %4s " $i ${COLOR_CODE[$i]}
+ color.set "${COLOR_CODE[$i]}"
+ color.set "40"
+ printf " Test "
+
+ color.set "1;47"
+ color.set "${COLOR_CODE[$i]}"
+ printf " Test "
+ color.reset
+
+ printf " %5s " ${BGCOLOR_CODE[$i]}
+ color.set ${BGCOLOR_CODE[$i]}
+ printf " Test "
+ color.reset
+ echo
+
+ done | sort
+ color.reset
+ echo "--------------------------------------------------"
+ echo
+ COLOR_DEBUG=$_debug
+}
+
+# little helper: sow defined presets and its preview
+function color.presets(){
+ local _label
+ local _value
+ local _colorvar
+ local _fg
+ local _bg
+
+ color.reset
+ local _debug=$COLOR_DEBUG
+ COLOR_DEBUG=0
+
+ if ! set | grep "^COLOR_PRESET_.*=(" >/dev/null; then
+ echo "INFO: No preset was defined yet."
+ echo "To set one define shell variables with an array of 2 colors:"
+ echo " COLOR_PRESET_<LABEL>=(<FOREGROUND> <BACKGROUND>)"
+ echo "For more help call 'color.help' or see the docs."
+ else
+ echo
+ echo "List of presets:"
+ echo
+ echo "---------------------------------------------------------------------"
+ echo "label | foreground | background | example"
+ echo "---------------------------------------------------------------------"
+
+ set | grep "^COLOR_PRESET_.*=(" | while read -r line
+ do
+ _label=$( cut -f 1 -d '=' <<< "$line" | cut -f 3- -d '_')
+ _example=$( color.print "$_label" "example for peset '$_label'" )
+ _colorvar="COLOR_PRESET_${_label}"
+ eval "_fg=\${$_colorvar[0]}"
+ eval "_bg=\${$_colorvar[1]}"
+
+ printf "%-10s | %-12s | %-12s | %-50s\n" "$_label" "${_fg}" "${_bg}" "$_example"
+ done
+ echo "---------------------------------------------------------------------"
+ echo
+ fi
+ COLOR_DEBUG=$_debug
+}
+# ----------------------------------------------------------------------
+# FUNCTIONS :: set color
+# ----------------------------------------------------------------------
+
+# set background color
+# param string backround color 0..7 OR color name eg "black" or a valid color value eg "1;30"
+# param string optional: foreground color
+function color.bg(){
+ color.__wd "$FUNCNAME $1"
+ color.__fgorbg "$1" 4
+ test -n "$2" && color.fg "$2"
+}
+
+# get a color of a preset
+# param string name of preset
+# param integer array index; 0= foreground; 1= background
+function color.__getpresetcolor(){
+ local _label=$1
+ local _index=$2
+ local _colorvar
+ _colorvar="COLOR_PRESET_${_label}"
+ eval "echo \${$_colorvar[$_index]}"
+}
+
+# set foreground color
+# param string foreground color 0..7 OR color name eg "black" or a valid color value eg "1;30"
+# param string optional: background color
+function color.fg(){
+ color.__wd "$FUNCNAME $1"
+ color.__fgorbg "$1" 3
+ test -n "$2" && color.bg "$2"
+}
+
+
+# set colors of a preset
+# param string label of a preet
+function color.preset(){
+ if color.__isapreset "$1"; then
+ local _colorvar
+ local _colfg=$( color.__getpresetcolor "$1" 0)
+ local _colbg=$( color.__getpresetcolor "$1" 1)
+ color.reset
+ test -n "$_colfg" && color.__fgorbg "$_colfg" 3
+ test -n "$_colbg" && color.__fgorbg "$_colbg" 4
+ else
+ >&2 echo "ERROR: this value is not a valid preset: $1. See 'color.presets' to see current presets."
+ fi
+}
+
+# ----------------------------------------------------------------------
+
+# reset all colors to terminal default
+function color.reset(){
+ color.__wd "$FUNCNAME"
+ color.set "0"
+}
+
+# start bold text
+function color.bold(){
+ color.__wd "$FUNCNAME"
+ color.set "1"
+}
+
+# start underline text
+function color.underline(){
+ color.__wd "$FUNCNAME"
+ color.set "4"
+}
+
+# start blinking text
+function color.blink(){
+ color.__wd "$FUNCNAME"
+ color.set "5"
+}
+
+# start inverted text
+function color.invert(){
+ color.__wd "$FUNCNAME"
+ color.set "7"
+}
+
+# ----------------------------------------------------------------------
+
+# write ansicode to set color combination
+# param string color 1 as ansi value
+# param string color N as ansi value
+function color.set(){
+ local _out=
+ if color.__usecolor; then
+ for mycolor in $*
+ do
+ color.__wd "$FUNCNAME: processing color value '${mycolor}'"
+ _out+="${mycolor}"
+ done
+ color.__wd "$FUNCNAME: output is '\e[${_out}m'"
+ printf "\e[${_out}m"
+ else
+ color.__wd "$FUNCNAME: skipping - coloring is disabled."
+ fi
+}
+
+# ----------------------------------------------------------------------
+# FUNCTIONS :: print
+# ----------------------------------------------------------------------
+
+# show a colored text WITH carriage return
+# param string foreground color as code / name / value
+# param string optional: background color as code / name / value
+# param string text to print
+function color.echo(){
+ color.__wd "$FUNCNAME $*"
+ local _param1="$1"
+ local _param2="$2"
+ shift 1
+ shift 1
+ color.print "$_param1" "$_param2" "$*"
+ echo
+}
+
+# show a colored text without carriage return
+# param string foreground color as code / name / value or preset
+# param string optional: background color as code / name / value
+# param string text to print
+function color.print(){
+ color.__wd "$FUNCNAME $*"
+ if color.__isacolor "$1"; then
+ if color.__isacolor "$2"; then
+ color.fg "$1" "$2"
+ shift 1
+ shift 1
+ else
+ color.fg "$1"
+ shift 1
+ fi
+ elif color.__isapreset "$1"; then
+ color.preset "$1"
+ shift 1
+ else
+ >&2 echo -n "ERROR: Wrong color values detected. Command was: colors.print $*"
+ fi
+ echo -n "$*"
+ color.reset
+}
+
+# ======================================================================
diff --git a/tests/example_01_simple_get.sh b/tests/example_01_simple_get.sh
new file mode 100755
index 0000000000000000000000000000000000000000..4943e6c5decf841b1439ba861459766a2711fbb8
--- /dev/null
+++ b/tests/example_01_simple_get.sh
@@ -0,0 +1,101 @@
+#!/bin/bash
+# ======================================================================
+#
+# REST API CLIENT
+#
+# Example 1 :: Simple GET request
+# This is an introduction, how it works.
+#
+# ======================================================================
+
+cd "$( dirname "$0" )" || exit
+
+# shellcheck source=../rest-api-client.sh
+. ../rest-api-client.sh
+
+# shellcheck source=color.class.sh
+. color.class.sh
+
+sURL="http://www.iml.unibe.ch/"
+
+# ----------------------------------------------------------------------
+# FUNCTIONS
+# ----------------------------------------------------------------------
+
+function wait4Return(){
+
+ local _sleep
+ _sleep=${1:-10} # default 10
+ echo
+ echo
+ color.print "cyan" "Press return to continue or wait $_sleep seconds ... "
+ read -r -s -t $_sleep dummy
+ echo
+ echo
+ echo
+}
+
+
+# ----------------------------------------------------------------------
+# MAIN
+# ----------------------------------------------------------------------
+
+color.fg "yellow"
+cat <<EOH
+----------------------------------------------------------------------
+
+Example 1 :: Simple GET request
+This is a introduction, how it works.
+
+----------------------------------------------------------------------
+
+EOH
+color.reset
+
+
+echo "We need to initialize the client with 'http.init' before each new request."
+echo
+color.echo "green" "> http.init"
+http.init
+
+wait4Return 10
+
+echo "Let's make a GET request to our example url $sURL."
+echo
+color.echo "green" "> http.makeRequest GET '$sURL'"
+http.makeRequest GET "$sURL"
+echo "Done."
+echo "Here is no output."
+echo "Now we can read information from the response."
+
+wait4Return 10
+
+color.echo "green" "> http.getStatuscode - This returns the Http status code"
+http.getStatuscode
+echo
+sleep 1
+
+color.echo "green" "> http.getStatus - You get the Status as string OK|Redirect|Error"
+http.getStatus
+echo
+sleep 1
+
+color.echo "green" "> http.getResponseHeader - print Http response header"
+http.getResponseHeader
+echo
+sleep 1
+
+color.echo "green" "> http.getResponseData - get data from curl"
+http.getResponseData
+echo
+sleep 1
+
+color.echo "green" "> http.getResponse - get response body"
+http.getResponse
+echo
+sleep 1
+
+echo
+echo "That's all for the moment. Bye."
+
+# ----------------------------------------------------------------------
\ No newline at end of file