<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def load_weights(self):
 """ Load weights by evaluating self.network_weights_loader, if needed. After calling this, self.network_weights_loader will be None and self.network_weights will be the weights list, if available. """

        if self.network_weights_loader:
            self.network_weights = self.network_weights_loader()
            self.network_weights_loader = None