code: public LiveDataSeries addJavaScriptParameter(final String parameterName, final String javascriptExpression) {
  		this.javascriptParameters.put(parameterName, javascriptExpression);
  		return this;
  	}
docs: Adds a javascript parameter that will be passed into the
  {@link #update(LiveDataUpdateEvent)} method.
  
  @param parameterName
  the name of the parameter
  @param javascriptExpression
  a javascript expression. The value this expression evaluates to
  will be transmitted to the server via AJAX and will be passed into
  update(LiveDataUpdateEvent). The javascript expression
  may be a function call or a literal. If it is a literal string,
  you have to surround the string with single quotes. Don't use
  double quotes in an expression since they are not escaped correctly.
  @return this object for chaining