type hints: models/vae.py (#346)

* type hints: models/vae.py

* modify typings in vae.py
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>
Co-authored-by: Anton Lozhkov <anton@huggingface.co>

src/diffusers/models/vae.py

@@ -487,7 +487,7 @@ class AutoencoderKL(ModelMixin, ConfigMixin):
         self.quant_conv = torch.nn.Conv2d(2 * latent_channels, 2 * latent_channels, 1)
         self.post_quant_conv = torch.nn.Conv2d(latent_channels, latent_channels, 1)
 
-    def encode(self, x, return_dict: bool = True):
+    def encode(self, x: torch.FloatTensor, return_dict: bool = True) -> AutoencoderKLOutput:
         h = self.encoder(x)
         moments = self.quant_conv(h)
         posterior = DiagonalGaussianDistribution(moments)