pub fn vertex_mut(&mut self, index: usize) -> Result<&mut V> {
        self.vertices
            .get_mut(&index)
            .ok_or_else(|| ErrorKind::GraphVertexNotFound(index).into())
    }
// Fetches a mutable instance of a vertex.
Fetches a mutable instance of a vertex.
Fetches a mutable instance of a vertex .
pub fn vertex_mut(&mut self, index: usize) -> Result<&mut V> {
        self.vertices
            .get_mut(&index)
            .ok_or_else(|| ErrorKind::GraphVertexNotFound(index).into())
    }
pub fn vertex_mut ( & mut self , index : usize ) -> Result < & mut V > { self . vertices . get_mut ( & index ) . ok_or_else ( | | ErrorKind :: GraphVertexNotFound ( index ) . into ( ) ) }
Fetches a mutable instance of a vertex.
Fetches a mutable instance of a vertex .
&mut self
index
usize
&mut self
index
usize