`DGraph::with_path` should take the ownership of `self` to avoid cloning.

[Remzi Yang]

stateright/src/test_util.rs

Lines 71 to 89 in 54f037c

 pub fn with_path(&self, path: Vec<u8>) -> Self { 
     let mut src = *path.first().unwrap(); 
     DGraph { 
         inits: { 
             let mut inits = self.inits.clone(); 
             inits.insert(src); 
             inits 
         }, 
         edges: { 
             let mut edges = self.edges.clone(); 
             for &dst in path.iter().skip(1) { 
                 edges.entry(src).or_default().insert(dst); 
                 src = dst; 
             } 
             edges 
         }, 
         property: self.property.clone(), 
     } 
 } 

It is better to let with_path consume self to avoid coping.

pub fn with_path(mut self, path: Vec<u8>) -> Self {
    ...
}