NdArray implementations don't throw IllegalRankException as documented if no coordinates provided

Instead, when no coordinates are provided, we return the scalar at (0, 0, ...). Is this an important idiom that we are preserving, or a questionable choice, or simply a bug?

Here's an example of an abstract method of FloatNdArray that is documented to throw IllegalRankException:

 /**
   * Returns the float value of the scalar found at the given coordinates.
   *
   * . . .
   *
   * @param coordinates coordinates of the scalar to resolve
   * @return value of that scalar
   * @throws IndexOutOfBoundsException if some coordinates are outside the limits of their respective dimension
   * @throws IllegalRankException if number of coordinates is not sufficient to access a scalar element
   */
  float getFloat(long... coordinates);

Here's the implementation in FloatDenseNdArray:

  @Override
  public float getFloat(long... indices) {
    return buffer.getFloat(positionOf(indices, true));
  }

But if indices.length == 0, then positionOf does not throw the claimed IllegalRankException:

  long positionOf(long[] coords, boolean isValue) {
    if (coords == null || coords.length == 0) {
      return 0;
    }
    Validator.coordinates(dimensions, coords, isValue);
    return dimensions.positionOf(coords);
  }

Comience con el contrato documentado de FloatNdArray.getFloat y compárelo con FloatDenseNdArray.getFloat y positionOf, especialmente con la rama de coordenadas cero. Determine si devolver el escalar en la posición 0 es intencionado o infringe el comportamiento de excepciones documentado; se considera terminado cuando el comportamiento y su documentación coinciden, con la cobertura relevante añadida o actualizada si el proyecto la proporciona.