{
  "type": "File",
  "start":0,"end":38,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":38}},
  "program": {
    "type": "Program",
    "start":0,"end":38,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":38}},
    "sourceType": "module",
    "interpreter": null,
    "body": [
      {
        "type": "VariableDeclaration",
        "start":0,"end":38,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":38}},
        "declarations": [
          {
            "type": "VariableDeclarator",
            "start":4,"end":38,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":38}},
            "id": {
              "type": "Identifier",
              "start":4,"end":9,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":9},"identifierName":"f"},
              "name": "f",
              "typeAnnotation": {
                "type": "TypeAnnotation",
                "start":6,"end":9,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":9}},
                "typeAnnotation": {
                  "type": "ExistsTypeAnnotation",
                  "start":8,"end":9,"loc":{"start":{"line":1,"column":8},"end":{"line":1,"column":9}}
                }
              }
            },
            "init": {
              "type": "ArrowFunctionExpression",
              "start":12,"end":38,"loc":{"start":{"line":1,"column":12},"end":{"line":1,"column":38}},
              "predicate": null,
              "returnType": {
                "type": "TypeAnnotation",
                "start":27,"end":32,"loc":{"start":{"line":1,"column":27},"end":{"line":1,"column":32}},
                "typeAnnotation": {
                  "type": "ExistsTypeAnnotation",
                  "start":30,"end":31,"loc":{"start":{"line":1,"column":30},"end":{"line":1,"column":31}}
                }
              },
              "id": null,
              "generator": false,
              "async": false,
              "params": [
                {
                  "type": "Identifier",
                  "start":13,"end":25,"loc":{"start":{"line":1,"column":13},"end":{"line":1,"column":25},"identifierName":"x"},
                  "name": "x",
                  "typeAnnotation": {
                    "type": "TypeAnnotation",
                    "start":15,"end":25,"loc":{"start":{"line":1,"column":15},"end":{"line":1,"column":25}},
                    "typeAnnotation": {
                      "type": "UnionTypeAnnotation",
                      "start":17,"end":25,"loc":{"start":{"line":1,"column":17},"end":{"line":1,"column":25}},
                      "types": [
                        {
                          "type": "NullLiteralTypeAnnotation",
                          "start":17,"end":21,"loc":{"start":{"line":1,"column":17},"end":{"line":1,"column":21}}
                        },
                        {
                          "type": "ExistsTypeAnnotation",
                          "start":24,"end":25,"loc":{"start":{"line":1,"column":24},"end":{"line":1,"column":25}}
                        }
                      ]
                    }
                  }
                }
              ],
              "body": {
                "type": "BlockStatement",
                "start":36,"end":38,"loc":{"start":{"line":1,"column":36},"end":{"line":1,"column":38}},
                "body": [],
                "directives": []
              }
            }
          }
        ],
        "kind": "let"
      }
    ],
    "directives": []
  }
}