code: def size(f, unit='B', fileStore=None):
      
      divisor = return_bytes(unit)
      fileID = process_infile(f, fileStore)[0]
      return fileID.size / divisor
docs: Returns the size of a file in bytes.
  
      :param f: Filename
      :param unit: Return the byte size in these units (gigabytes, etc.).
      :return: