code: function getTranslation(m, dst) {
    dst = dst || v3.create();
    dst[0] = m[12];
    dst[1] = m[13];
    dst[2] = m[14];
    return dst;
  }
docs: Returns the translation component of a 4-by-4 matrix as a vector with 3
  entries.
  @param {module:twgl/m4.Mat4} m The matrix.
  @param {module:twgl/v3.Vec3} [dst] vector.
  @return {module:twgl/v3.Vec3} The translation component of m.
  @memberOf module:twgl/m4