bool matrixEquals(Matrix4 a, Matrix4 b)

Returns true if the given matrices are exactly equal, and false otherwise. Null values are assumed to be the identity matrix.

Source 

static bool matrixEquals(Matrix4 a, Matrix4 b) {
  if (identical(a, b))
    return true;
  assert(a != null || b != null);
  if (a == null)
    return isIdentity(b);
  if (b == null)
    return isIdentity(a);
  assert(a != null && b != null);
  return a.storage[0] == b.storage[0]
      && a.storage[1] == b.storage[1]
      && a.storage[2] == b.storage[2]
      && a.storage[3] == b.storage[3]
      && a.storage[4] == b.storage[4]
      && a.storage[5] == b.storage[5]
      && a.storage[6] == b.storage[6]
      && a.storage[7] == b.storage[7]
      && a.storage[8] == b.storage[8]
      && a.storage[9] == b.storage[9]
      && a.storage[10] == b.storage[10]
      && a.storage[11] == b.storage[11]
      && a.storage[12] == b.storage[12]
      && a.storage[13] == b.storage[13]
      && a.storage[14] == b.storage[14]
      && a.storage[15] == b.storage[15];
}