Fix docstring in GraphTransformer (#97) (#104)

This PR fixes the docstring in GraphTransformer as mentioned in #97.

* Fix docstring in GraphTransformer (#97)

* trim trailing whitespace

src/gflownet/models/graph_transformer.py

@@ -25,11 +25,10 @@ class GraphTransformer(nn.Module):
     conditional information, since they condition the output). The graph features are projected to
     virtual nodes (one per graph), which are fully connected.
 
-    The per node outputs are the concatenation of the final (post graph-convolution) node embeddings
-    and of the final virtual node embedding of the graph each node corresponds to.
+    The per node outputs are the final (post graph-convolution) node embeddings.
 
     The per graph outputs are the concatenation of a global mean pooling operation, of the final
-    virtual node embeddings, and of the conditional information embedding.
+    node embeddings, and of the final virtual node embeddings.
     """
 
     def __init__(self, x_dim, e_dim, g_dim, num_emb=64, num_layers=3, num_heads=2, num_noise=0, ln_type="pre"):
@@ -134,8 +133,8 @@ def forward(self, g: gd.Batch, cond: torch.Tensor):
                 o = o + l_h * scale + shift
                 o = o + ff(norm2(o, aug_batch))
 
-        glob = torch.cat([gnn.global_mean_pool(o[: -c.shape[0]], g.batch), o[-c.shape[0] :]], 1)
-        o_final = torch.cat([o[: -c.shape[0]]], 1)
+        o_final = o[: -c.shape[0]]
+        glob = torch.cat([gnn.global_mean_pool(o_final, g.batch), o[-c.shape[0] :]], 1)
         return o_final, glob