code: public final void varifyParam(final int mNumber) throws TTXPathException {
  
          if (mNumber < mMin || mNumber > mMax) {
              throw EXPathError.XPST0017.getEncapsulatedException();
          }
      }
docs: Checks if the number of input arguments of this function is a valid
  according to the function specification in <a
  href="http://www.w3.org/TR/xquery-operators/"> XQuery 1.0 and XPath 2.0
  Functions and Operators</a>. Throws an XPath error in case of a non-valid
  number.
  
  @param mNumber
  number of given function arguments
  @throws TTXPathException
  if function call fails.