code: protected String getArgumentValue(String arg, String[] args, ConsoleWrapper stdin, PrintStream stdout) {
          for (int i = 1; i < args.length; i++) {
              String key = args[i].split("=")[0];
              if (key.equals(arg)) {
                  return getValue(args[i]);
              }
          }
          return null;
      }
docs: Gets the value for the specified argument String.
  
  No validation is done in the format of args as it is assumed to
  have been done previously.
  
  @param arg    Argument name to resolve a value for
  @param args   List of arguments. Assumes the script name is included and therefore minimum length is 2.
  @param stdin  Standard in interface
  @param stdout Standard out interface
  @return Value of the argument
  @throws IllegalArgumentException if the argument is defined but no value is given.