How to use the bidict._common.ValueDuplicationError function in bidict

"""Base class for bidict exceptions."""


class DuplicationError(BidictException):
    """Base class for exceptions raised when uniqueness is violated."""


class KeyDuplicationError(DuplicationError):
    """Raised when a given key is not unique."""


class ValueDuplicationError(DuplicationError):
    """Raised when a given value is not unique."""


class KeyAndValueDuplicationError(KeyDuplicationError, ValueDuplicationError):
    """
    Raised when a given item's key and value are not unique.

return
            # key and val each duplicate a different existing item.
            if on_dup_kv is RAISE:
                raise KeyAndValueDuplicationError(key, val)
            elif on_dup_kv is IGNORE:
                return
            # else on_dup_kv is OVERWRITE. Fall through to return on last line.
        elif isdupkey:
            if on_dup_key is RAISE:
                raise KeyDuplicationError(key)
            elif on_dup_key is IGNORE:
                return
            # else on_dup_key is OVERWRITE. Fall through to return on last line.
        elif isdupval:
            if on_dup_val is RAISE:
                raise ValueDuplicationError(val)
            elif on_dup_val is IGNORE:
                return
            # else on_dup_val is OVERWRITE. Fall through to return on last line.
        # else neither isdupkey nor isdupval.
        return isdupkey, isdupval, invbyval, fwdbykey