add test for related concept
add test for related concept

jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry,jonphipps/Metadata-Registry