### Question:
Vector3f extends AVector3 { public static Vector3f zero() { return new Vector3f(); } private  Vector3f(); private  Vector3f(final double x, final double y, final double z); static Vector3f fromXYZ(final double x, final double y, final double z); static Vector3f from2d(final IVector2 xy, final double z); static Vector3f copy(final IVector3 original); static Vector3f zero(); @Override IVector3 copy(); @Override IVector3 getXYZVector(); @Override double x(); @Override double y(); @Override double z(); static final Vector3f X_AXIS; static final Vector3f Y_AXIS; static final Vector3f Z_AXIS; static final Vector3f ZERO_VECTOR; static final Vector3f UNINITIALIZED; }### Answer:
@Test public void testZero() { Vector3f zero = Vector3f.zero(); assertThat(zero.x()).isEqualTo(0.0); assertThat(zero.y()).isEqualTo(0.0); }