static String mul ( String s , int k ) {
  StringBuilder sb = new StringBuilder ( ) ;
  while ( k -- >= 1 ) {
    sb . append ( s ) ;
  }
  return sb . toString ( ) ;
}

static String mul ( String s , int k ) { StringBuilder sb = new StringBuilder ( ) ; while ( k -- >= 1 ) { sb . append ( s ) ; } return sb . toString ( ) ; }
(method_declaration (modifiers) type: (type_identifier) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list)))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) body: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))) (return_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))