Added the `GenerationMixin`

Updated the `Florence2LanguageForConditionalGeneration` to inherit from the `GenerationMixin`

modeling_florence2.py

@@ -29,6 +29,8 @@ from einops import rearrange
 from timm.models.layers import DropPath, trunc_normal_
 
 from transformers.modeling_utils import PreTrainedModel
+from transformers.generation.utils import GenerationMixin
+
 from transformers.utils import (
     ModelOutput,
     add_start_docstrings,
@@ -2059,7 +2061,7 @@ class Florence2LanguageModel(Florence2LanguagePreTrainedModel):
         )
 
 
-class Florence2LanguageForConditionalGeneration(Florence2LanguagePreTrainedModel):
+class Florence2LanguageForConditionalGeneration(Florence2LanguagePreTrainedModel, GenerationMixin):
     base_model_prefix = "model"
     _tied_weights_keys = ["encoder.embed_tokens.weight", "decoder.embed_tokens.weight", "lm_head.weight"]
     _keys_to_ignore_on_load_missing = ["final_logits_bias"]