def _set_building_params(cls, *, eta=None, minclustersize=None, epsilon=None, maxblocksize=None):
        """Put the parameters in the C++ backend."""
        if epsilon is not None:
            cls.lib.setepsilon.restype = None
            cls.lib.setepsilon.argtypes = [ ctypes.c_double ]
            cls.lib.setepsilon(epsilon)

        if eta is not None:
            cls.lib.seteta.restype = None
            cls.lib.seteta.argtypes = [ ctypes.c_double ]
            cls.lib.seteta(eta)

        if minclustersize is not None:
            cls.lib.setminclustersize.restype = None
            cls.lib.setminclustersize.argtypes = [ ctypes.c_int ]
            cls.lib.setminclustersize(minclustersize)

        if maxblocksize is not None:
            cls.lib.setmaxblocksize.restype = None
            cls.lib.setmaxblocksize.argtypes = [ ctypes.c_int ]
            cls.lib.setmaxblocksize(maxblocksize)