code: def resolve(self, value):
          
          if self is value:
              raise TypeError('Cannot resolve promise with itself.')
  
          if isinstance(value, Promise):
              value.done(self.resolve, self.reject)
              return
  
          if self._state != 'pending':
              raise RuntimeError('Promise is no longer pending.')
  
          self.value = value
          self._state = 'resolved'
          callbacks = self._callbacks
          self._callbacks = None
          for callback in callbacks:
              callback(value)
docs: Resolves the promise with the given value.