public static void main ( String [ ] args ) {
  int x1 = - 1 , y1 = 2 ;
  int x2 = 3 , y2 = - 6 ;
  midpoint ( x1 , x2 , y1 , y2 ) ;
}

public static void main ( String [ ] args ) { int x1 = - 1 , y1 = 2 ; int x2 = 3 , y2 = - 6 ; midpoint ( x1 , x2 , y1 , y2 ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_literal))) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_literal)))) (expression_statement (method_invocation name: (identifier) arguments: (argument_list (identifier) (identifier) (identifier) (identifier))))))