code: public static String getScriptVar(String scriptName, String key) {
  		validateScriptName(scriptName);
  		return getScriptVarImpl(scriptName, key);
  	}
docs: Gets a variable from the script with the given name.
  
  @param scriptName the name of the script.
  @param key the key of the variable.
  @return the value of the variable, might be {@code null} if no value was previously set.
  @throws IllegalArgumentException if the {@code scriptName} is {@code null}.
  @since TODO add version