protected void MapProperty <TProperty>(int columnIndex,
Expression <Func <TEntity, TProperty> > mappingExpression)
{
// get propertyname
var propertyName = GetPropertyNameFromExpression(mappingExpression);
// create ipropertymapper
var mapper = PropertyMapperFactory.CreateMapperUtf8 <TEntity>(propertyName);
var mapping = new CsvPropertyMapping(columnIndex, mapper);
_mappings.Insert(columnIndex, mapping);
_numCols++;
}
