function createWrapper(func, bitmask, partialArgs, partialRightArgs, thisArg, arity) {
      var isBind = bitmask & 1,
          isBindKey = bitmask & 2,
          isCurry = bitmask & 4,
          isCurryBound = bitmask & 8,
          isPartial = bitmask & 16,
          isPartialRight = bitmask & 32;

      if (!isBindKey && !isFunction(func)) {
        throw new TypeError;
      }
      if (isPartial && !partialArgs.length) {
        bitmask &= ~16;
        isPartial = partialArgs = false;
      }
      if (isPartialRight && !partialRightArgs.length) {
        bitmask &= ~32;
        isPartialRight = partialRightArgs = false;
      }
      var bindData = func && func.__bindData__;
      if (bindData && bindData !== true) {
        // clone `bindData`
        bindData = slice(bindData);
        if (bindData[2]) {
          bindData[2] = slice(bindData[2]);
        }
        if (bindData[3]) {
          bindData[3] = slice(bindData[3]);
        }
        // set `thisBinding` is not previously bound
        if (isBind && !(bindData[1] & 1)) {
          bindData[4] = thisArg;
        }
        // set if previously bound but not currently (subsequent curried functions)
        if (!isBind && bindData[1] & 1) {
          bitmask |= 8;
        }
        // set curried arity if not yet set
        if (isCurry && !(bindData[1] & 4)) {
          bindData[5] = arity;
        }
        // append partial left arguments
        if (isPartial) {
          push.apply(bindData[2] || (bindData[2] = []), partialArgs);
        }
        // append partial right arguments
        if (isPartialRight) {
          unshift.apply(bindData[3] || (bindData[3] = []), partialRightArgs);
        }
        // merge flags
        bindData[1] |= bitmask;
        return createWrapper.apply(null, bindData);
      }
      // fast path for `_.bind`
      var creater = (bitmask == 1 || bitmask === 17) ? baseBind : baseCreateWrapper;
      return creater([func, bitmask, partialArgs, partialRightArgs, thisArg, arity]);
    }
Creates a function that, when called, either curries or invokes `func`
with an optional `this` binding and partially applied arguments.

@private
@param {Function|string} func The function or method name to reference.
@param {number} bitmask The bitmask of method flags to compose.
 The bitmask may be composed of the following flags:
 1 - `_.bind`
 2 - `_.bindKey`
 4 - `_.curry`
 8 - `_.curry` (bound)
 16 - `_.partial`
 32 - `_.partialRight`
@param {Array} [partialArgs] An array of arguments to prepend to those
 provided to the new function.
@param {Array} [partialRightArgs] An array of arguments to append to those
 provided to the new function.
@param {*} [thisArg] The `this` binding of `func`.
@param {number} [arity] The arity of `func`.
@returns {Function} Returns the new function.