support graphql-codegen document operations
https://www.graphql-code-generator.com/

operations
```
operations: {"query":{"kind":"Document","definitions":[{"kind":"OperationDefinition","operation":"mutation","name":{"kind":"Name","value":"mergeSubmit"},"variableDefinitions":[{"kind":"VariableDefinition","variable":{"kind":"Variable","name":{"kind":"Name","value":"jobId"}},"type":{"kind":"NonNullType","type":{"kind":"NamedType","name":{"kind":"Name","value":"String"}}}},{"kind":"VariableDefinition","variable":{"kind":"Variable","name":{"kind":"Name","value":"xlsxFile"}},"type":{"kind":"NonNullType","type":{"kind":"NamedType","name":{"kind":"Name","value":"Upload"}}}}],"selectionSet":{"kind":"SelectionSet","selections":[{"kind":"Field","name":{"kind":"Name","value":"mergeSubmit"},"arguments":[{"kind":"Argument","name":{"kind":"Name","value":"jobId"},"value":{"kind":"Variable","name":{"kind":"Name","value":"jobId"}}},{"kind":"Argument","name":{"kind":"Name","value":"xlsxFile"},"value":{"kind":"Variable","name":{"kind":"Name","value":"xlsxFile"}}}]}]}}]},"variables":{"jobId":"987","xlsxFile":null}}
map: {"1":["variables.xlsxFile"]}
1: (binary)
```

This method is not currently supported, response
```
GraphQL queries must be strings. It looks like you're sending the internal graphql-js representation of a parsed query in your request instead of a request in the GraphQL query language. You can convert an AST to a string using the `print` function from `graphql`, or use a client like `apollo-client` which converts the internal representation to a string for you.
```