author CaMnter
  const toString = Object . prototype . toString ; param target export function isObject ( target ) { return '[object Object]' === toString . call ( target ) ; } param target export function isFunction ( target ) { return target && 'function' === typeof target ; } param target export function isString ( target ) { return target && 'string' === typeof target ; } param target export function isLegalString ( target ) { return target && isString ( target ) && '' !== target ; } param target export function isNumber ( target ) { return target && 'number' === typeof target ; } param target export function isLegalArray ( target ) { if ( ! target ) { return false ; } return Array . isArray ( target ) && target . length > 0 ; } /**
 * nothing to do
 */ export function nothingToDo ( ) { }