code: public String getVariableDecoded(String variableName) {
          String value = m_variableMap.get(variableName);
          if (value == null) {
              return null;
          }
          return Utils.urlDecode(value);
      }
docs: Get the URI-decoded value of the variable with the given name. Null is returned if
  there is no variable with the given name. This method calls
  {@link #getVariable(String)} and passes the result through
  {@link Utils#urlDecode(String)}.
  
  @param variableName  Variable name.
  @return              The value of requested variable URI-decoded, or null if there
  is no such variable.
  @see #getVariables()
  @see #getVariable(String)