src/promissory-arbiter.js
function startsWith (haystack, needle, startPosition) {
    startPosition = startPosition || 0;
    return haystack.lastIndexOf(needle, startPosition) === startPosition;
  }
function startsWith (haystack, needle, startPosition) {
    startPosition = startPosition || 0;
    return haystack.lastIndexOf(needle, startPosition) === startPosition;
  }
function startsWith ( haystack , needle , startPosition ) { startPosition = startPosition || 0 ; return haystack . lastIndexOf ( needle , startPosition ) === startPosition ; }
Determines whether a string begins with the characters of another string, returning true or false as appropriate.
Determines whether a string begins with the characters of another string returning true or false as appropriate .