equals( euler ) {

		return ( euler._x === this._x ) && ( euler._y === this._y ) && ( euler._z === this._z ) && ( euler._order === this._order );

	}
Returns `true` if this Euler instance is equal with the given one.

@param {Euler} euler - The Euler instance to test for equality.
@return {boolean} Whether this Euler instance is equal with the given one.