         self.count = 0
         return buffer
     }
-    
-    
+
+
     /// Returns the storage buffer index for a deque index.
     internal func bufferIndexForDequeIndex(index: Int) -> Int {
         let i = start + index
         if i >= capacity { return i - capacity }
         return i
     }
-    
+
     /// Returns the deque index for a storage buffer index.
     internal func dequeIndexForBufferIndex(i: Int) -> Int {
         if i >= start {

            elements.advanced(by: i).pointee = newValue
        }
    }
    
    internal func prepend(element: Element) {
        precondition(count < capacity)
        let i = start == 0 ? capacity - 1 : start - 1

        precondition(count >= n)
        buffer.removeRange(0 ..< n)
    }

    /// Remove the first `n` elements from this deque.
    ///
    /// - Requires: `count >= n`
