anchor.diff:    /// Current state for the flag "constant-update-2018"
     bool get constant_update_2018 => _enableFlags[0];
   
  +  /// Current state for the flag "control_flow_collections"
  +  bool get control_flow_collections => _enableFlags[3];
  +
     /// Current state for the flag "non-nullable"
     bool get non_nullable => _enableFlags[2];
   
  
positive.code:           constant_update_2018 ?? IsEnabledByDefault.constant_update_2018,
            set_literals ?? IsEnabledByDefault.set_literals,
            non_nullable ?? IsEnabledByDefault.non_nullable,
            spread_collections ?? IsEnabledByDefault.spread_collections,
            control_flow_collections ??
                IsEnabledByDefault.control_flow_collections,
          ];
  
    /// Decodes the strings given in [flags] into a representation of the set of
  
negative.code:   bool get set_literals => _enableFlags[1];
  
    /// Current state for the flag "spread_collections"
    bool get spread_collections => _enableFlags[4];
  
    /// Queries whether the given [feature] is enabled or disabled.
    bool isEnabled(ExperimentalFeature feature) => feature.isExpired
  