Evaluate the function with the specified arguments.
To the greatest extent possible, side-effects should be avoided in the definition of extension functions. The implementation evaluating an XPath expression is under no obligation to call extension functions in any particular order or any particular number of times.
@param args The arguments,
null is a valid value.
@return The result of evaluating the
XPath function as an
Object.
@throws XPathFunctionException If
args cannot be evaluated with this
XPath function.