code: def dataSetMissingValue(h5Dataset):
      
      attributes = h5Dataset.attrs
      if not attributes:
          return None # a premature optimization :-)
  
      for key in ('missing_value', 'MissingValue', 'missingValue', 'FillValue', '_FillValue'):
          if key in attributes:
              missingDataValue = attributes[key]
              if is_an_array(missingDataValue) and len(missingDataValue) == 1:
                  return missingDataValue[0] # In case of HDF-EOS and NetCDF files
              else:
                  return missingDataValue
      return None
docs: Returns the missingData given a HDF-5 dataset
  
          Looks for one of the following attributes: _FillValue, missing_value, MissingValue,
          missingValue. Returns None if these attributes are not found.
  
          HDF-EOS and NetCDF files seem to put the attributes in 1-element arrays. So if the
          attribute contains an array of one element, that first element is returned here.