static long difference ( long M , long N ) {
  return M + N ;
}

static long difference ( long M , long N ) { return M + N ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (return_statement (binary_expression left: (identifier) right: (identifier)))))