pub fn unique_signers(signers: Vec<&dyn Signer>) -> Vec<&dyn Signer>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where A: Allocator,
impl<A> Write for Vec<u8, A> where A: Allocator,
Removes duplicate signers while preserving order. O(n²)