fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        // `write!` is like `format!`, but it will write the formatted string
        // into a buffer (the first argument)
        write!(f, "( {} {} )\n( {} {} )", self.0, self.1, self.2, self.3)
    }
// `f` is a buffer, this method must write the formatted string into it
`f` is a buffer, this method must write the formatted string into it
` f ` is a buffer this method must write the formatted string into it
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        // `write!` is like `format!`, but it will write the formatted string
        // into a buffer (the first argument)
        write!(f, "( {} {} )\n( {} {} )", self.0, self.1, self.2, self.3)
    }
fn fmt ( & self , f : & mut Formatter ) -> fmt :: Result { // `write!` is like `format!`, but it will write the formatted string // into a buffer (the first argument) write ! ( f " \n " self 0 self 1 self 2 self 3 ) }
`f` is a buffer, this method must write the formatted string into it
` f ` is a buffer this method must write the formatted string into it
&self
f
&mut Formatter
&self
f
&mut Formatter