/// Return a new alphabet taking the union between this and other.
///
/// # Example
/// ```
/// use bio::alphabets;
///
/// let dna_alphabet = alphabets::Alphabet::new(b"ATCG");
/// let tokenize_alpha = alphabets::Alphabet::new(b"?|");
/// let alpha = dna_alphabet.union(&tokenize_alpha);
///
/// assert_eq!(alpha, alphabets::Alphabet::new(b"ATCG?|"));
/// ```
Return a new alphabet taking the union between this and other.
Return a new alphabet taking the union between this and other .
pub fn union(&self, other: &Alphabet) -> Self {
        return Alphabet {
            symbols: self.symbols.union(&other.symbols).collect(),
        };
    }
pub fn union ( & self , other : & Alphabet ) -> Self { return Alphabet { symbols : self . symbols . union ( & other . symbols ) . collect ( ) , } ; }
Return a new alphabet taking the union between this and other.
Return a new alphabet taking the union between this and other .
&self
other
&Alphabet
example
```
use bio::alphabets.

let dna_alphabet = alphabets::Alphabet::new(b"ATCG");
let tokenize_alpha = alphabets::Alphabet::new(b"?|");
let alpha = dna_alphabet.union(&tokenize_alpha).

assert_eq!(alpha, alphabets::Alphabet::new(b"ATCG?|"));
```
` ` ` use bio :: alphabets . let dna_alphabet = alphabets :: Alphabet :: new ( b " ATCG " ) ; let tokenize_alpha = alphabets :: Alphabet :: new ( b " ?| " ) ; let alpha = dna_alphabet . union ( &tokenize_alpha ) . assert_eq! ( alpha alphabets :: Alphabet :: new ( b " ATCG?| " )) ; ` ` `