private CustomEntityType CheckTypeCompatibility(object entityObject) { Debug.Assert(null != entityObject); CustomEntityType entityType = MetadataWorkspace.GetEntityType(entityObject.GetType()); if (!EntitySetType.BaseElementType.IsAssignableFrom(entityType)) { throw new InvalidOperationException(String.Format( "The base element type '{0}' of the entity set '{1}' is not compatible with " + "the entity type '{2}' of the object '{3}'.", EntitySetType.BaseElementType, EntitySetType.Name, entityType, entityObject )); } return(entityType); }