def METHOD_NAME(self, file: Path) -> None:
    """Imports metadata from any MCE/MCP file. Does not clear prior loaded data.
    This function can be called repeatedly on the same
    Mock instance to load up metadata from multiple files."""
    file_source: GenericFileSource = GenericFileSource(
        ctx=PipelineContext(run_id="test"), config=FileSourceConfig(path=str(file))
    )
    for wu in file_source.get_workunits():
        if isinstance(wu, MetadataWorkUnit):
            metadata = wu.get_metadata().get("metadata")
            mcps: Iterable[
                Union[
                    MetadataChangeProposal,
                    MetadataChangeProposalWrapper,
                ]
            ]
            if isinstance(metadata, MetadataChangeEvent):
                mcps = mcps_from_mce(metadata)
            elif isinstance(
                metadata, (MetadataChangeProposal, MetadataChangeProposalWrapper)
            ):
                mcps = [metadata]
            else:
                raise Exception(
                    f"Unexpected metadata type {type(metadata)}. Was expecting MCE, MCP or MCPW"
                )
            for mcp in mcps:
                assert mcp.entityUrn
                assert mcp.aspectName
                assert mcp.aspect
                if mcp.entityUrn not in self.entity_graph:
                    self.entity_graph[mcp.entityUrn] = {}
                self.entity_graph[mcp.entityUrn][mcp.aspectName] = mcp.aspect