def __init__(self, datafile, path='<STR_LIT>', nparams=dict(), attr_params=dict(),<EOL>mode='<STR_LIT:r>'):
super().__init__(datafile, path=path, nparams=nparams,<EOL>attr_params=attr_params, mode=mode)<EOL>if mode != '<STR_LIT:r>':<EOL><INDENT>self.h5file.create_group('<STR_LIT:/>', '<STR_LIT>',<EOL>'<STR_LIT>')<EOL>self.h5file.create_group('<STR_LIT:/>', '<STR_LIT>', '<STR_LIT>')<EOL><DEDENT>
Return a new HDF5 file to store simulation results.

        The HDF5 file has two groups:
        '/parameters'
            containing all the simulation numeric-parameters

        '/trajectories'
            containing simulation trajectories (positions, emission traces)

        If `mode='w'`, `datafile` will be overwritten (if exists).