code: def get_span_char_height(span, row_heights):
      
      start_row = span[0][0]
      row_count = get_span_row_count(span)
      total_height = 0
  
      for i in range(start_row, start_row + row_count):
          total_height += row_heights[i]
      total_height += row_count - 1
  
      return total_height
docs: Get the height of a span in the number of newlines it fills.
  
      Parameters
      ----------
      span : list of list of int
          A list of [row, column] pairs that make up the span
      row_heights : list of int
          A list of the number of newlines for each row in the table
  
      Returns
      -------
      total_height : int
          The height of the span in number of newlines