private string GetProperty(string definitionReference, params string[] propertyName)
        {
            PropertyIndex propertyIndex = new PropertyIndex(definitionReference, propertyName);

            if (_flatFileProperties.ContainsKey(propertyIndex))
            {
                return(_flatFileProperties[propertyIndex]);
            }
            else
            {
                return(null);
            }
        }
 protected bool Equals(PropertyIndex other)
 {
     return(_definitionReference == other._definitionReference &&
            _propertyNames.SequenceEqual(other._propertyNames));
 }