@staticmethod
def guess_flavour(line):
    """Guess which variant of PQR format this line is

        Parameters
        ----------
        line : str
          entire line of PQR file starting with ATOM/HETATM

        Returns
        -------
        flavour : str
          ORIGINAL / GROMACS / NO_CHAINID

        .. versionadded:: 0.18.0
        """
    fields = line.split()
    if len(fields) == 11:
        try:
            float(fields[-1])
        except ValueError:
            flavour = 'GROMACS'
        else:
            flavour = 'ORIGINAL'
    else:
        flavour = 'NO_CHAINID'
    return flavour
