nl_tokens: Similar to async . series () but instead accumulating the result in an Array it callbacks with the result of the last function in the array .
pl_tokens: function series ( arr , callback ) { if ( ! Array . isArray ( arr ) ) { throw new TypeError ( 'First parameter must be an Array' ) ; } callback = callback || noop ; let index = 0 ; let <mask> ; next ( ) ; function next ( err , result ) { if ( err ) { return callback ( err ) ; } if ( index === arr . length ) { return callback ( null , result ) ; } if ( sync ) { return process . nextTick ( function ( ) { sync = true ; arr [ index ++ ] ( next ) ; sync = false ; } ) ; } sync = true ; arr [ index ++ ] ( next ) ; sync = false ; } }