protected override void InvokeInternal(CommandProcessorContext cpc)
        {
            // safety check, this should never be hit
            Debug.Assert(ParentComplexType != null, "InvokeInternal is called when ParentComplexType is null.");
            if (ParentComplexType == null)
            {
                throw new InvalidOperationException("InvokeInternal is called when ParentComplexType is null");
            }

            Debug.Assert(!(Type == null && ComplexType == null), "InvokeInternal is called when Type or ComplexType is null.");
            if (Type == null
                && ComplexType == null)
            {
                throw new InvalidOperationException("InvokeInternal is called when Type and ComplexType is null");
            }

            // check for uniqueness
            string msg;
            if (!ModelHelper.ValidateComplexTypePropertyName(ParentComplexType, Name, true, out msg))
            {
                throw new CommandValidationFailedException(msg);
            }

            // check for ComplexType circular definition
            if (ComplexType != null)
            {
                if (ModelHelper.ContainsCircularComplexTypeDefinition(ParentComplexType, ComplexType))
                {
                    throw new CommandValidationFailedException(
                        String.Format(
                            CultureInfo.CurrentCulture, Resources.Error_CircularComplexTypeDefinitionOnAdd, ComplexType.LocalName.Value));
                }
            }
            // create the property
            Property property = null;
            if (Type != null)
            {
                var conceptualProperty = new ConceptualProperty(ParentComplexType, null);
                conceptualProperty.ChangePropertyType(Type);
                property = conceptualProperty;
            }
            else
            {
                var complexProperty = new ComplexConceptualProperty(ParentComplexType, null);
                complexProperty.ComplexType.SetRefName(ComplexType);
                property = complexProperty;
            }
            Debug.Assert(property != null, "property should not be null");
            if (property == null)
            {
                throw new ItemCreationFailureException();
            }

            // set the name and add to the parent entity
            property.LocalName.Value = Name;
            ParentComplexType.AddProperty(property);

            // set other attributes of the property
            if (Nullable != null)
            {
                property.Nullable.Value = (Nullable.Value ? BoolOrNone.TrueValue : BoolOrNone.FalseValue);
            }

            XmlModelHelper.NormalizeAndResolve(property);
            _createdProperty = property;
        }
 private static Property CreateConceptualProperty(ConceptualEntityType parentEntity, string name, string type, InsertPropertyPosition insertPosition)
 {
     var property = new ConceptualProperty(parentEntity, null, insertPosition);
     property.LocalName.Value = name;
     property.ChangePropertyType(type);
     return property;
 }