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