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