code: public Matrix4d set4x3(Matrix4x3dc mat) {
          m00 = mat.m00();
          m01 = mat.m01();
          m02 = mat.m02();
          m10 = mat.m10();
          m11 = mat.m11();
          m12 = mat.m12();
          m20 = mat.m20();
          m21 = mat.m21();
          m22 = mat.m22();
          m30 = mat.m30();
          m31 = mat.m31();
          m32 = mat.m32();
          properties &= mat.properties() & ~(PROPERTY_PERSPECTIVE);
          return this;
      }
docs: Set the upper 4x3 submatrix of this {@link Matrix4d} to the given {@link Matrix4x3dc}
  and don't change the other elements.
  
  @see Matrix4x3dc#get(Matrix4d)
  
  @param mat
  the {@link Matrix4x3dc}
  @return this