Remove circular import in projected_words_embedder.py

combo/modules/token_embedders/projected_words_embedder.py

@@ -5,7 +5,6 @@ from overrides import overrides
 
 from combo.config import Registry
 from combo.data.vocabulary import Vocabulary
-from combo.nn.base import Linear
 from combo.modules.token_embedders.token_embedder import TokenEmbedder
 from combo.modules.token_embedders.embedding import Embedding
 
@@ -27,7 +26,7 @@ class ProjectedWordEmbedder(Embedding):
                  vocab_namespace: str = "tokens",
                  pretrained_file: str = None,
                  vocabulary: Vocabulary = None,
-                 projection_layer: Linear = None): # Change to Optional[Linear]
+                 projection_layer: Optional["Linear"] = None): # Change to Optional[Linear]
         super().__init__(
             embedding_dim=embedding_dim,
             num_embeddings=num_embeddings,