code: function invoke(seq, method) { var args
          args = slice(arguments, 2)
  
          return map(seq, function(value) {
              return nilp(value)?               undefined
                   : callablep(value[method])?  value[method].apply(value, args)
                   : /* not-callable? */        undefined })
      }
docs: /// Function invoke //////////////////////////////////////////////////////  (seq:Sequence, method:String[, args...]) ↦ Array  Returns a sequence with the result of invoking the given method name for all objects.  Items that have no such method are mapped to `undefined`.