code: def normalize_reference_name(name):
      
      lower_name = name.strip().lower()
      for reference in Species._reference_names_to_species.keys():
          if reference.lower() == lower_name:
              return reference
      raise ValueError("Reference genome '%s' not found" % name)
docs: Search the dictionary of species-specific references to find a reference
      name that matches aside from capitalization.
  
      If no matching reference is found, raise an exception.