function setDual(out, q) {
    out[4] = q[0];
    out[5] = q[1];
    out[6] = q[2];
    out[7] = q[3];
    return out;
  }
Set the dual component of a dual quat to the given quaternion

@param {quat2} out the receiving quaternion
@param {ReadonlyQuat} q a quaternion representing the dual part
@returns {quat2} out
@function