[BUG] OCI GenAI Grok Argument not supported: logit_bias

[danielkec]

Describe the bug

As reported by @lefred, when connecting to Grok model over Lc4j OCI GenAI integration, logit-bias is set even when empty map is configured.

Log and Stack trace

Error returned by Chat operation in GenerativeAiInference service.(400, 400, false) {"code":"400","error":"Argument not supported: logit_bias"} (opc-request-id: E7C2D8EA8A3B4A65B29910259A8FFE52/2642B63A975BD74AF5DA92A156DAC756/5C5FD7CCAF30156F0FF76DE0809E33C2)
Timestamp: 2025-08-26T07:37:32.544Z
Client version: Oracle-JavaSDK/3.68.1
Request Endpoint: https://inference.generativeai.us-ashburn-1.oci.oraclecloud.com/20231130/actions/chat
Additional Properties in error response: {}

Minimal Example to Reproduce

Expected behavior

property should be set only when collection is not empty

Please complete the following information:

• LangChain4j Community version: 1.3.0
• LangChain4j Community Component you used (e.g. langchain4j-community-clickhouse): langchain4j-community-oci-genai
• Java version: 21
• Helidon version: 1.3.0-M1