/// <summary>
/// Selects a set of SQL expressions. This is a variant of `select` that accepts SQL expressions.
///
/// df.SelectExpr("colA", "colB as newName", "abs(colC)")
///
/// </summary>
/// <param name="columnExpressions"></param>
/// <returns></returns>
public DataFrame SelectExpr(params string[] columnExpressions)
{
return(new DataFrame(dataFrameProxy.SelectExpr(columnExpressions), sparkContext));
}