constructor( x = 0, y = 0, z = 0, order = Euler.DEFAULT_ORDER ) {

		/**
		 * This flag can be used for type testing.
		 *
		 * @type {boolean}
		 * @readonly
		 * @default true
		 */
		this.isEuler = true;

		this._x = x;
		this._y = y;
		this._z = z;
		this._order = order;

	}
Constructs a new euler instance.

@param {number} [x=0] - The angle of the x axis in radians.
@param {number} [y=0] - The angle of the y axis in radians.
@param {number} [z=0] - The angle of the z axis in radians.
@param {string} [order=Euler.DEFAULT_ORDER] - A string representing the order that the rotations are applied.