pub fn integer_value(&self) -> Option<&BigInt> {
        match self.value {
            LitExprValue::Integer(ref v) => Some(v),
            _ => None,
        }
    }
/// Return the literal's integer value, or `None` if it is not an integer.
Return the literal's integer value, or `None` if it is not an integer.
Return the literal ' s integer value or ` None ` if it is not an integer .
pub fn integer_value(&self) -> Option<&BigInt> {
        match self.value {
            LitExprValue::Integer(ref v) => Some(v),
            _ => None,
        }
    }
pub fn integer_value ( & self ) -> Option < & BigInt > { match self . value { LitExprValue :: Integer ( ref v ) => Some ( v ) , _ => None , } }
Return the literal's integer value, or `None` if it is not an integer.
Return the literal ' s integer value or ` None ` if it is not an integer .
&self
&self