community[patch]: introduce convert_to_secret() to bananadev llm (#14283)

- **Description:** Per #12165, this PR add to BananaLLM the function
convert_to_secret_str() during environment variable validation.
- **Issue:** #12165
- **Tag maintainer:** @eyurtsev
- **Twitter handle:** @treewatcha75751

---------

Co-authored-by: Bagatur <22008038+baskaryan@users.noreply.github.com>

libs/community/langchain_community/llms/bananadev.py

@@ -1,10 +1,10 @@
 import logging
-from typing import Any, Dict, List, Mapping, Optional
+from typing import Any, Dict, List, Mapping, Optional, cast
 
 from langchain_core.callbacks import CallbackManagerForLLMRun
 from langchain_core.language_models.llms import LLM
-from langchain_core.pydantic_v1 import Extra, Field, root_validator
-from langchain_core.utils import get_from_dict_or_env
+from langchain_core.pydantic_v1 import Extra, Field, SecretStr, root_validator
+from langchain_core.utils import convert_to_secret_str, get_from_dict_or_env
 
 from langchain_community.llms.utils import enforce_stop_tokens
 
@@ -38,7 +38,7 @@ class Banana(LLM):
     """Holds any model parameters valid for `create` call not
     explicitly specified."""
 
-    banana_api_key: Optional[str] = None
+    banana_api_key: Optional[SecretStr] = None
 
     class Config:
         """Configuration for this pydantic config."""
@@ -66,8 +66,8 @@ class Banana(LLM):
     @root_validator()
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that api key and python package exists in environment."""
-        banana_api_key = get_from_dict_or_env(
-            values, "banana_api_key", "BANANA_API_KEY"
+        banana_api_key = convert_to_secret_str(
+            get_from_dict_or_env(values, "banana_api_key", "BANANA_API_KEY")
         )
         values["banana_api_key"] = banana_api_key
         return values
@@ -103,7 +103,7 @@ class Banana(LLM):
             )
         params = self.model_kwargs or {}
         params = {**params, **kwargs}
-        api_key = self.banana_api_key
+        api_key = cast(SecretStr, self.banana_api_key)
         model_key = self.model_key
         model_url_slug = self.model_url_slug
         model_inputs = {
@@ -113,7 +113,7 @@ class Banana(LLM):
         }
         model = Client(
             # Found in main dashboard
-            api_key=api_key,
+            api_key=api_key.get_secret_value(),
             # Both found in model details page
             model_key=model_key,
             url=f"https://{model_url_slug}.run.banana.dev",