code: def while_stmt(self, while_loc, test, while_colon_loc, body, else_opt):
          
          stmt = ast.While(test=test, body=body, orelse=[],
                           keyword_loc=while_loc, while_colon_loc=while_colon_loc,
                           else_loc=None, else_colon_loc=None,
                           loc=while_loc.join(body[-1].loc))
          if else_opt:
              stmt.else_loc, stmt.else_colon_loc, stmt.orelse = else_opt
              stmt.loc = stmt.loc.join(stmt.orelse[-1].loc)
  
          return stmt
docs: while_stmt: 'while' test ':' suite ['else' ':' suite]