joint.all.js
function wrap(value, wrapper) {
      if (!isFunction(wrapper)) {
        throw new TypeError;
      }
      return function() {
        var args = [value];
        push.apply(args, arguments);
        return wrapper.apply(this, args);
      };
    }
function wrap(value, wrapper) {
      if (!isFunction(wrapper)) {
        throw new TypeError;
      }
      return function() {
        var args = [value];
        push.apply(args, arguments);
        return wrapper.apply(this, args);
      };
    }
Creates a function that provides `value` to the wrapper function as its
first argument. Additional arguments provided to the function are appended
to those provided to the wrapper function. The wrapper is executed with
the `this` binding of the created function.

@static
@memberOf _
@category Functions
@param {*} value The value to wrap.
@param {Function} wrapper The wrapper function.
@returns {Function} Returns the new function.
@example

var hello = function(name) { return 'hello ' + name; };
hello = _.wrap(hello, function(func) {
return 'before, ' + func('moe') + ', after';
});
hello();
// => 'before, hello moe, after'