public Set<ExecutableElement> consumeMethods(Context context) {
    return ImmutableSet.of();
  }
Returns a possibly empty set of abstract methods that this Extension intends to implement. This
will prevent AutoValue from generating an implementation, in cases where it would have, and it
will also avoid complaints about abstract methods that AutoValue doesn't expect. The default
set returned by this method is empty.

<p>Each returned method must be one of the abstract methods in {@link
Context#abstractMethods()}.

<p>For example, Android's {@code Parcelable} interface includes a <a
href="http://developer.android.com/reference/android/os/Parcelable.html#writeToParcel(android.os.Parcel,int)">method</a>
{@code void writeToParcel(Parcel, int)}. Normally AutoValue would not know what to do with that
abstract method. But an {@code AutoValueExtension} that understands {@code Parcelable} can
provide a useful implementation and return the {@code writeToParcel} method here. That will
prevent a warning about the method from AutoValue.

@param context the Context of the code generation for this class.
value/src/main/java/com/google/auto/value/extension/AutoValueExtension.java