No methods listed for "You have these unused @Provider methods"

package com.vidal.rest.sdk;

import com.vidal.rest.sdk.converters.AtomConverter;
import com.vidal.rest.sdk.converters.AtomDeserializerFactory;
import dagger.Module;
import dagger.ObjectGraph;
import dagger.Provides;
import retrofit.RestAdapter;
import retrofit.converter.Converter;

@Module
public class VidalAPI {

    private final String uri;

    private VidalAPI(String uri) {
        this.uri = uri;
    }

    public static Resources at(String uri) {
        ObjectGraph graph = ObjectGraph.create(new VidalAPI(uri));
        return graph.get(ResourceFactory.class);
    }

    @Provides
    ResourceFactory resourceFactory(RestAdapter restAdapter) {
        return new ResourceFactory(restAdapter);
    }

    @Provides
    RestAdapter restAdapter(Converter converter) {
        return new RestAdapter.Builder()
                .setConverter(converter)
                .setEndpoint(uri)
                .build();
    }

    @Provides
    Converter converter(AtomDeserializerFactory deserializers) {
        return new AtomConverter(deserializers);
    }

    @Provides
    AtomDeserializerFactory deserializers() {
        return new AtomDeserializerFactory();
    }

}

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[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/fbiville/Projects/vidal-rest-sdk/src/main/java/com/vidal/rest/sdk/VidalAPI.java:[11,7] error: Graph validation failed: You have these unused @Provider methods:
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
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