/// <summary>
/// Adds a navigation property to the <paramref name="entityType"/>. This method creates an association type
/// in order to add the navigation property.
/// Returns the modified entity type for composability.
/// </summary>
/// <param name="entityType">The <see cref="EntityType"/> to add the navigation property to.</param>
/// <param name="propertyName">The name of the property to add.</param>
/// <param name="otherEndType">The type of the other end of the navigation property.</param>
/// <param name="isSingletonRelationship">true if the navigation property is of singleton cardinality; false for a cardinality many. Default is false.</param>
/// <returns>The <paramref name="entityType"/> instance after adding the navigation property to it.</returns>
public static EntityType NavigationProperty(this EntityType entityType, string propertyName, EntityType otherEndType, bool isSingletonRelationship = false)
{
ExceptionUtilities.CheckArgumentNotNull(entityType, "entityType");
ExceptionUtilities.CheckArgumentNotNull(propertyName, "propertyName");
EntityModelSchema model = entityType.Model();
// create the association type between the two entity types
AssociationType associationType = model.AssociationType(entityType, otherEndType, isSingletonRelationship);
// add the navigation property to the generated entity type
entityType.Add(new NavigationProperty(propertyName, associationType, associationType.Ends[0], associationType.Ends[1]));
return(entityType);
}