docs: def getFilenames(self,pixels=None):
          """
          Return the requested filenames.
  
          Parameters:
          -----------
          pixels : requeseted pixels
  
          Returns:
          --------
          filenames : recarray
          """
          logger.debug("Getting filenames...")
          if pixels is None:
              return self.filenames
          else:
              return self.filenames[np.in1d(self.filenames['pix'],pixels)]