Fix init to accept kwargs

agent.json

@@ -1,4 +1,31 @@
 {
+  "reranker.predict": {
+    "traces": [],
+    "train": [],
+    "demos": [],
+    "signature": {
+      "instructions": "Assess the relevance of a document to a query.",
+      "fields": [
+        {
+          "prefix": "Query:",
+          "description": "${query}"
+        },
+        {
+          "prefix": "Document:",
+          "description": "${document}"
+        },
+        {
+          "prefix": "Reasoning: Let's think step by step in order to",
+          "description": "${reasoning}"
+        },
+        {
+          "prefix": "Relevance Score:",
+          "description": "${relevance_score}"
+        }
+      ]
+    },
+    "lm": null
+  },
   "metadata": {
     "dependency_versions": {
       "python": "3.11",