- 
          w
          ↔ num         
        
- 
          
                  read / write, override-getter 
- 
          x
          ↔ num         
        
- 
          
                  read / write, override-getter 
- 
          y
          ↔ num         
        
- 
          
                  read / write, override-getter 
- 
          z
          ↔ num         
        
- 
          
                  read / write, override-getter 
- 
          hashCode
          → int         
        
- 
          The hash code for this object. [...]
                  read-only, inherited 
- 
          runtimeType
          → Type         
        
- 
          A representation of the runtime type of the object.
                  read-only, inherited