df_append_integer Subroutine

    subroutine df_append_integer(df, col, header)
        type(data_frame), intent(inout) :: df
        integer(ik), dimension(:), intent(in) :: col
        character(len=*), intent(in), optional :: header

        type(column) :: new_col
        integer :: new_index

        call df % validate_column_addition(header, size(col))
        call df % resize_storage()

        call df % increment_num_cols()
        new_index = df % ncols()
        call new_col % new(col)
        call df % set_data_col(new_index, new_col)

        if (present(header)) then
            call df % set_header_at_index(new_index, header)
        end if
    end subroutine df_append_integer