public MetadataAssociationEnd(string name, string entityName, MetadataAssociationMultiplicity multiplicity = MetadataAssociationMultiplicity.One)
		{
			if(string.IsNullOrWhiteSpace(entityName))
				throw new ArgumentNullException("entityName");

			_entityName = entityName.Trim();
			_multiplicity = multiplicity;
			_name = string.IsNullOrWhiteSpace(name) ? _entityName : name.Trim();
			_constraints = new MetadataAssociationEndConstraintCollection(this);
		}
        public MetadataAssociationEnd(string name, string entityName, MetadataAssociationMultiplicity multiplicity = MetadataAssociationMultiplicity.One)
        {
            if (string.IsNullOrWhiteSpace(entityName))
            {
                throw new ArgumentNullException("entityName");
            }

            _entityName   = entityName.Trim();
            _multiplicity = multiplicity;
            _name         = string.IsNullOrWhiteSpace(name) ? _entityName : name.Trim();
            _constraints  = new MetadataAssociationEndConstraintCollection(this);
        }