public static String getParam(String defaultValue) {
		return System.getProperty("param", defaultValue);
	}
Get the parameter passed by controller. When it's executed in the
validation mode, always returns the given default value.

@param defaultValue default value
@return param. default value string if the param was not provided.
@since 3.2.3
ngrinder-runtime/src/main/java/net/grinder/util/GrinderUtils.java