/**
    Get the lower bound of the interval.

    Returns ```None``` if the interval is empty.

    # Example

    ```
    use advanced_collections::interval::{Interval, LowerBound};
    fn main() {
       let i = Interval::open(3,5);
       let l = i.lower();;
       assert_eq!(l, Some(&LowerBound::new(3, false)));
    }
    ```
    */
Get the lower bound of the interval.
Get the lower bound of the interval .
pub fn lower(&self) -> Option<&LowerBound<T>> {
        match &self.imp{
            None => None,
            Some(a) => Some(&a.lo)
        }
    }
pub fn lower ( & self ) -> Option < & LowerBound < T > > { match & self . imp { None => None , Some ( a ) => Some ( & a . lo ) } }
Get the lower bound of the interval.
Get the lower bound of the interval .
&self
example
```
use advanced_collections::interval::{Interval, LowerBound};
fn main() {
let i = Interval::open(3,5);
let l = i.lower();;
assert_eq!(l, Some(&LowerBound::new(3, false)));
}
```
` ` ` use advanced_collections :: interval :: { Interval LowerBound } ; fn main () { let i = Interval :: open ( 3 5 ) ; let l = i . lower () ;; assert_eq! ( l Some ( &LowerBound :: new ( 3 false ))) ; } ` ` `