class Prawn::Table::Cells

def columns(col_spec)


table.columns(3..4) # selects columns four and five
table.column(0) # selects first column

column numbers; most commonly a number or a range.
anything that responds to the === operator selecting a set of 0-based
Limits selection to the given column or columns. +col_spec+ can be 
def columns(col_spec)
  index_cells unless defined?(@indexed) && @indexed
  col_spec = transform_spec(col_spec, @first_column, @column_count)
  Cells.new(@columns[col_spec] ||= select { |c|
              col_spec.respond_to?(:include?) ?
                col_spec.include?(c.column) : col_spec === c.column })
end