code: def to_html(self):
          
          # Apply bootstrap alignment classes first
          if self.align is 'left':
              if self.style_class is None:
                  self.style_class = 'text-left'
              else:
                  self.style_class += ' text-left'
          elif self.align is 'right':
              if self.style_class is None:
                  self.style_class = 'text-right'
              else:
                  self.style_class += ' text-right'
          elif self.align is 'center':
              if self.style_class is None:
                  self.style_class = 'text-center'
              else:
                  self.style_class += ' text-center'
  
          # Special case for when we want to put a nested table in a cell
          # We don't use isinstance because of recursive imports with table
          class_name = self.content.__class__.__name__
          if class_name in ['BulletedList', 'Table', 'Image', 'Message']:
              html = self.content.to_html()
          else:
              html = self.content.to_html(wrap_slash=self.wrap_slash)
  
          # Check if we have a header or not then render
          if self.header_flag is True:
              return '<th%s colspan=%i>%s</th>\n' % (
                  self.html_attributes(), self.span, html)
          else:
              return '<td%s colspan=%i>%s</td>\n' % (
                  self.html_attributes(), self.span, html)
docs: Render a Cell MessageElement as html
  
          :returns: The html representation of the Cell MessageElement
          :rtype: basestring