in propfuzz/src/traits.rs [46:55]
fn execute(&self, test_runner: &mut TestRunner) -> Result<(), TestError<Self::Value>>;
/// Formats a failing test case for displaying to the user.
///
/// The default implementation calls the `fmt::Debug` implementation on the value.
///
/// The default implementation for the `#[propfuzz]` macro prints out variable names and values.
fn fmt_value(&self, value: &Self::Value, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{:?}", value)
}