function getLongestArray (arrays) {
  var lengths = arrays.map(array => array.length)
  return Math.max.apply(null, lengths)
}
function getLongestArray (arrays) {
  var lengths = arrays.map(array => array.length)
  return Math.max.apply(null, lengths)
}
function getLongestArray ( arrays ) { var lengths = arrays . map ( array => array . length ) return Math . max . apply ( null , lengths ) }
Array of arrays in.. Returns the length of the longest one
@returns {number}
@private
Array of arrays in .. Returns the length of the longest one