function baseMerge(object, source, customizer, stackA, stackB) {
	      if (!isObject(object)) {
	        return object;
	      }
	      var isSrcArr = isArrayLike(source) && (isArray(source) || isTypedArray(source)),
	          props = isSrcArr ? undefined : keys(source);

	      arrayEach(props || source, function(srcValue, key) {
	        if (props) {
	          key = srcValue;
	          srcValue = source[key];
	        }
	        if (isObjectLike(srcValue)) {
	          stackA || (stackA = []);
	          stackB || (stackB = []);
	          baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB);
	        }
	        else {
	          var value = object[key],
	              result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
	              isCommon = result === undefined;

	          if (isCommon) {
	            result = srcValue;
	          }
	          if ((result !== undefined || (isSrcArr && !(key in object))) &&
	              (isCommon || (result === result ? (result !== value) : (value === value)))) {
	            object[key] = result;
	          }
	        }
	      });
	      return object;
	    }
The base implementation of `_.merge` without support for argument juggling,
multiple sources, and `this` binding `customizer` functions.

@private
@param {Object} object The destination object.
@param {Object} source The source object.
@param {Function} [customizer] The function to customize merged values.
@param {Array} [stackA=[]] Tracks traversed source objects.
@param {Array} [stackB=[]] Associates values with source counterparts.
@returns {Object} Returns `object`.