code: def define_grid(self, matrix):
          
          self.style['grid-template-areas'] = ''.join("'%s'"%(' '.join(x)) for x in matrix)
docs: Populates the Table with a list of tuples of strings.
  
          Args:
              matrix (list): list of iterables of strings (lists or something else). 
                  Items in the matrix have to correspond to a key for the children.