code: @GET
      @Path("/relationshipdef/name/{name}")
      @Produces(Servlets.JSON_MEDIA_TYPE)
      public AtlasRelationshipDef getRelationshipDefByName(@PathParam("name") String name) throws AtlasBaseException {
          AtlasRelationshipDef ret = typeDefStore.getRelationshipDefByName(name);
  
          return ret;
      }
docs: Get the relationship definition by it's name (unique)
  @param name relationship name
  @return relationship definition
  @throws AtlasBaseException
  @HTTP 200 On successful lookup of the the relationship definition by it's name
  @HTTP 404 On Failed lookup for the given name