pub fn iter_mut<'this>(
        &'this mut self,
    ) -> impl Iterator<Item = (EntityId, &'this mut C)> + 'this {
        self.items.iter_mut().map(|(&id, c)| (id, c))
    }
/// Mutably iterate over all the components in this [`Container`].
Mutably iterate over all the components in this [`Container`].
Mutably iterate over all the components in this [ ` Container ` ] .
pub fn iter_mut<'this>(
        &'this mut self,
    ) -> impl Iterator<Item = (EntityId, &'this mut C)> + 'this {
        self.items.iter_mut().map(|(&id, c)| (id, c))
    }
pub fn iter_mut < ' this > ( & ' this mut self , ) -> impl Iterator < Item = ( EntityId , & ' this mut C ) > + ' this { self . items . iter_mut ( ) . map ( | ( & id , c ) | ( id , c ) ) }
Mutably iterate over all the components in this [`Container`].
Mutably iterate over all the components in this [ ` Container ` ] .
&'this mut self