from openforcefield.topology.molecule import (
    Atom,
    Bond,
    BondChargeVirtualSite,
    DivalentLonePairVirtualSite,
    FrozenMolecule,
    Molecule,
    MonovalentLonePairVirtualSite,
    Particle,
    TrivalentLonePairVirtualSite,
    VirtualSite,
)
from openforcefield.topology.topology import (
    DuplicateUniqueMoleculeError,
    ImproperDict,
    NotBondedError,
    SortedDict,
    Topology,
    TopologyAtom,
    TopologyBond,
    TopologyMolecule,
    TopologyVirtualSite,
    ValenceDict,
)

from openforcefield.topology.molecule import (
    Atom,
    Bond,
    BondChargeVirtualSite,
    DivalentLonePairVirtualSite,
    FrozenMolecule,
    Molecule,
    MonovalentLonePairVirtualSite,
    Particle,
    TrivalentLonePairVirtualSite,
    VirtualSite,
)
from openforcefield.topology.topology import (
    DuplicateUniqueMoleculeError,
    ImproperDict,
    NotBondedError,
    SortedDict,
    Topology,
    TopologyAtom,
    TopologyBond,
    TopologyMolecule,
    TopologyVirtualSite,
    TopologyVirtualParticle,
    ValenceDict,
)

add VirtualParticle to __init__ for topology tests