code: def datasets_index_mappings():
      """The index mapping definition for the main datasets index"""
      return {
          "properties": {
              "id": {"type": "keyword"},
              "tags": {
                  "type": "nested",
                  "properties": {
                      "key": {"type": "keyword"},
                      "value": {"type": "text"},
                  },
              },
              "metadata": {
                  "type": "nested",
                  "properties": {
                      "key": {"type": "keyword"},
                      "value": {"type": "text"},
                  },
              },
          }
      }
  
label_desc: Use image node_id 1 for calling a global function with example usage: datasets_index_mappings() and returns: dict