pub fn column_max(&self) -> Option<&'_ String> {
        if self.entries.len() > 1 {
            return self.entries.last().unwrap().as_ref();
        }
        None
    }
/// Returns the lexicographical maximum value in the column. None is
/// returned only if the column does not contain any non-null values.
Returns the lexicographical maximum value in the column. None is
returned only if the column does not contain any non-null values.
Returns the lexicographical maximum value in the column . None is returned only if the column does not contain any non - null values .
pub fn column_max(&self) -> Option<&'_ String> {
        if self.entries.len() > 1 {
            return self.entries.last().unwrap().as_ref();
        }
        None
    }
pub fn column_max ( & self ) -> Option < & ' _ String > { if self . entries . len ( ) > 1 { return self . entries . last ( ) . unwrap ( ) . as_ref ( ) ; } None }
Returns the lexicographical maximum value in the column.
Returns the lexicographical maximum value in the column .
&self
&self