nl_tokens: Polyfill Object . assign
pl_tokens: function assign ( target ) { var sources = Array . prototype . <mask> . call ( arguments , 1 ) ; function assignArgument ( previous , source ) { Object . keys ( source ) . forEach ( function assignItem ( key ) { previous [ key ] = source [ key ] ; // eslint-disable-line no-param-reassign } ) ; return previous ; } return sources . reduce ( assignArgument , target ) ; }