ljharb
set-function-length 
Set a function’s length.
Arguments:
fn: the functionlength: the new length. Must be an integer between 0 and 2**32.loose: Optional. If true, and the length fails to be set, do not throw. Default false.
Returns fn.
Usage
var setFunctionLength = require('set-function-length');
var assert = require('assert');
function zero() {}
function one(_) {}
function two(_, __) {}
assert.equal(zero.length, 0);
assert.equal(one.length, 1);
assert.equal(two.length, 2);
assert.equal(setFunctionLength(zero, 10), zero);
assert.equal(setFunctionLength(one, 11), one);
assert.equal(setFunctionLength(two, 12), two);
assert.equal(zero.length, 10);
assert.equal(one.length, 11);
assert.equal(two.length, 12);