documentation, types, and style fixes

1 files changed, 15 insertions, 2 deletions

diff --git a/bsfs/graph/graph.py b/bsfs/graph/graph.py
index 4a36ff6..87f7a31 100644
--- a/bsfs/graph/graph.py
+++ b/bsfs/graph/graph.py
@@ -25,8 +25,15 @@ __all__: typing.Sequence[str] = (
 ## code ##
 
 class Graph():
+    """The Graph class is
+
+    The Graph class provides a convenient interface to query and access a graph.
+    Since it logically builds on the concept of graphs it is easier to
+    navigate than raw triple stores. Naturally, it uses a triple store
+    as *backend*. It also controls actions via access permissions to a *user*.
+
     """
-    """
+
     # link to the triple storage backend.
     _backend: TripleStoreBase
 
@@ -81,8 +88,14 @@ class Graph():
         return self
 
     def nodes(self, node_type: URI, guids: typing.Iterable[URI]) -> _nodes.Nodes:
+        """Return nodes *guids* of type *node_type* as a `bsfs.graph.Nodes` instance.
+
+        Note that the *guids* need not to exist (however, the *node_type* has
+        to be part of the schema). Inexistent guids will be created (using
+        *node_type*) once some data is assigned to them.
+
         """
-        node_type = self.schema.node(node_type)
+        type_ = self.schema.node(node_type)
         # NOTE: Nodes constructor materializes guids.
         return _nodes.Nodes(self._backend, self._user, type_, guids)