Add get method to CatalogEndpoints

Author: DarthMax

src/graphdatascience/procedure_surface/api/catalog/catalog_endpoints.py

@@ -16,6 +16,22 @@
 
 
 class CatalogEndpoints(ABC):
+    @abstractmethod
+    def get(self, graph_name: str) -> GraphV2:
+        """Retrieve a handle to a graph from the graph catalog.
+
+        Parameters
+        ----------
+        graph_name
+            The name of the graph.
+
+        Returns
+        -------
+        GraphV2
+            A handle to the graph.
+        """
+        pass
+
     @abstractmethod
     def construct(
         self,

src/graphdatascience/procedure_surface/arrow/catalog/catalog_arrow_endpoints.py

@@ -56,6 +56,11 @@ def __init__(
             protocol_version = ProtocolVersionResolver(query_runner).resolve()
             self._project_protocol = ProjectProtocol.select(protocol_version)
 
+    def get(self, graph_name: str) -> GraphV2:
+        if not self.list(graph_name):
+            raise ValueError(f"A graph with name '{graph_name}' does not exist in the catalog.")
+        return get_graph(graph_name, self._arrow_client)
+
     def project(
         self,
         graph_name: str,

src/graphdatascience/procedure_surface/cypher/catalog_cypher_endpoints.py

@@ -39,6 +39,11 @@ def __init__(self, cypher_runner: Neo4jQueryRunner, arrow_client: GdsArrowClient
         self._cypher_runner = cypher_runner
         self._arrow_client = arrow_client
 
+    def get(self, graph_name: str) -> GraphV2:
+        if not self.list(graph_name):
+            raise ValueError(f"A graph with name '{graph_name}' does not exist in the catalog.")
+        return get_graph(graph_name, self.cypher_runner)
+
     def construct(
         self,
         graph_name: str,