src/serialize/TwoVector.js
/**
     * Copy values from another TwoVector into this TwoVector
     *
     * @param {TwoVector} sourceObj the other vector
     * @return {TwoVector} returns self
     */
Copy values from another TwoVector into this TwoVector
@param {TwoVector} sourceObj the other vector
@return {TwoVector} returns self
Copy values from another TwoVector into this TwoVector @param { TwoVector } sourceObj the other vector @return { TwoVector } returns self
copy(sourceObj) {
        this.x = sourceObj.x;
        this.y = sourceObj.y;
        return this;
    }
copy ( sourceObj ) { this . x = sourceObj . x ; this . y = sourceObj . y ; return this ; }
Copy values from another TwoVector into this TwoVector
 @param {TwoVector} sourceObj the other vector
 @return {TwoVector} returns self
Copy values from another TwoVector into this TwoVector @param { TwoVector } sourceObj the other vector @return { TwoVector } returns self