gson request methods annotation

RequestMethod.java

import android.support.annotation.IntDef;
import com.android.volley.Request;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@IntDef({
        Request.Method.DEPRECATED_GET_OR_POST,
        Request.Method.GET,
        Request.Method.POST,
        Request.Method.PUT,
        Request.Method.DELETE,
        Request.Method.HEAD,
        Request.Method.OPTIONS,
        Request.Method.TRACE,
        Request.Method.PATCH,
})
@Retention(RetentionPolicy.SOURCE)
public @interface RequestMethod {
}

public Request<JSONObject> createJsonRequest(@RequestMethod final int method, @NotNull final String url, @NotNull String json, @NotNull final IResponse<JSONObject> callback, @Nullable Map<String, String> headerParams);