fetching data from GraphQL server through apollo environment through its client

Question

I am storing the data in json format in GraphQL server and making a query like:

query {
  symptoms{
    id
    name
    picUrl
  }
}

Now I have to fetch it from the server using its client. My app gradle.build file is as follows:

dependencies{
    compile 'com.apollographql.android:api:0.1.0' 
    compile 'com.squareup.retrofit2:retrofit:2.1.0' // retrofit2
    compile 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0' 
    compile 'com.apollographql.android:converter-pojo:0.1.0'
    compile 'junit:junit:4.12'
}

and in module gradle.build I have:

dependencies {
        classpath 'com.apollographql.apollo:gradle-plugin:0.3.3'
        classpath 'com.apollographql.android:gradle-plugin:0.1.0'
}

Now in the Adapter class I need to write the code to fetch the data. I am following this link https://github.com/apollographql/apollo-android But I am getting error while writing this code itself:

ApolloClient apolloClient;
apolloClient.newCall(FeedQuery.builder()

How to resolve this issue?