static Object readObjectFrom(Input input, Schema<?> schema, Object owner,
            IdStrategy strategy, int number) throws IOException
    {
        final Schema<Object> derivedSchema = strategy.resolvePojoFrom(input,
                number).getSchema();
        
        final Object pojo = derivedSchema.newMessage();
        
        if (input instanceof GraphInput)
        {
            // update the actual reference.
            ((GraphInput) input).updateLast(pojo, owner);
        }
        
        derivedSchema.mergeFrom(input, pojo);
        return pojo;
    }
Will be used if {@link RuntimeEnv#POJO_SCHEMA_ON_COLLECTION_FIELDS} is enabled and the
field is assignable from Collection.

@author David Yu
@created May 19, 2016
protostuff-runtime/src/main/java/io/protostuff/runtime/PolymorphicPojoCollectionSchema.java