Add page iterator helper for retrieving single page.
Add page iterator helper for retrieving single page.

yaoxiaoyong/github,davengeo/github,piotrmurach/github,firstval/github,samphilipd/github,peter-murach/github,durai145/github,befairyliu/github,MalachiTatum/github,anabhilash619/github,joshsoftware/github,cocktail-io/github,GistBox/github,wicky-info/github