Query times out with missing variable

[SPahooja]

Describe the bug Executing a query excepting an argument, times out in case the query is run with an undefined variable without reaching the resolver when using the AsyncTaskDecorator solution to enable async execution

Schema Example

extend type Query {
    countries(filter: CountryFilter!): [Country!]!
}

Query:

query Test($filter: CountryFilter!){
  countries(filter: $filter) {
    id
  }
}

Response:

{
  "errors": [
    {
      "message": "Execution canceled because timeout was reached",
      "locations": []
    }
  ],
  "data": null
}

Exception in thread "graphql-exec-2" graphql.execution.NonNullableValueCoercedAsNullException: Variable 'filter' has coerced Null value for NonNull type 'CountryFilter!'
	at graphql.execution.ValuesResolver.externalValueToInternalValueForVariables(ValuesResolver.java:407)
	at graphql.execution.ValuesResolver.coerceVariableValues(ValuesResolver.java:94)
	at graphql.analysis.QueryTraverser.coerceVariables(QueryTraverser.java:64)
	at graphql.analysis.QueryTraverser.<init>(QueryTraverser.java:60)
	at graphql.analysis.QueryTraverser.<init>(QueryTraverser.java:40)
	at graphql.analysis.QueryTraverser$Builder.build(QueryTraverser.java:297)
	at graphql.analysis.MaxQueryDepthInstrumentation.newQueryTraverser(MaxQueryDepthInstrumentation.java:92)
	at graphql.analysis.MaxQueryDepthInstrumentation.lambda$beginValidation$2(MaxQueryDepthInstrumentation.java:57)
	at graphql.execution.instrumentation.SimpleInstrumentationContext.onCompleted(SimpleInstrumentationContext.java:51)
	at graphql.execution.instrumentation.ChainedInstrumentation$ChainedInstrumentationContext.lambda$onCompleted$1(ChainedInstrumentation.java:238)
	at graphql.com.google.common.collect.ImmutableList.forEach(ImmutableList.java:405)
	at graphql.execution.instrumentation.ChainedInstrumentation$ChainedInstrumentationContext.onCompleted(ChainedInstrumentation.java:238)
	at graphql.GraphQL.validate(GraphQL.java:600)
	at graphql.GraphQL.parseAndValidate(GraphQL.java:562)
	at graphql.GraphQL.lambda$parseValidateAndExecute$10(GraphQL.java:531)
	at graphql.execution.preparsed.NoOpPreparsedDocumentProvider.getDocument(NoOpPreparsedDocumentProvider.java:15)
	at graphql.GraphQL.parseValidateAndExecute(GraphQL.java:533)
	at graphql.GraphQL.executeAsync(GraphQL.java:502)
	at graphql.kickstart.execution.GraphQLInvoker.executeAsync(GraphQLInvoker.java:37)
	at graphql.kickstart.execution.GraphQLInvoker.execute(GraphQLInvoker.java:28)
	at graphql.kickstart.servlet.HttpRequestInvokerImpl.invoke(HttpRequestInvokerImpl.java:164)
	at graphql.kickstart.servlet.HttpRequestInvokerImpl.lambda$invokeAndHandleAsync$2(HttpRequestInvokerImpl.java:79)

Expected behavior Return an error about the missing variable