问题
How would I write a protractor function that will search the page for a string of text and return a state of whether or not that string of text is present on the page, visible, hidden, etc.
The idea is to fulfill the step definitions for "I shall see" such that I can say "I shall see" for all visible elements, and "I should not see" for hidden elements"
来源：https://stackoverflow.com/questions/23791225/protractor-match-text