static boolean d ( int i ) {
  String s = String . valueOf ( i ) ;
  HashSet < Character > k = new HashSet < > ( ) ;
  for ( int j = 0 ;
  j < s . length ( ) ;
  j ++ ) {
    k . add ( s . charAt ( j ) ) ;
  }
  return k . size ( ) == 1 ;
}

static boolean d ( int i ) { String s = String . valueOf ( i ) ; HashSet < Character > k = new HashSet < > ( ) ; for ( int j = 0 ; j < s . length ( ) ; j ++ ) { k . add ( s . charAt ( j ) ) ; } return k . size ( ) == 1 ; }
(method_declaration (modifiers) type: (boolean_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments)) arguments: (argument_list)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))))) (return_statement (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))))