     strings2.append("B")
     XCTAssertFalse(strings2.asSequence().all { $0 == "A"} )
     
-    XCTAssertTrue(empty.asSequence().all {$0 == "A"} )
+    XCTAssertTrue(emptyStrings.asSequence().all {$0 == "A"} )
     
   }
   

    
    XCTAssertTrue(numbers.asSequence().last() == 9)
    
    if let last = empty.asSequence().last() {
      XCTAssertTrue(false)
    } else {
      XCTAssertTrue(true)
    }
    
  }
  
  

    
    XCTAssertTrue(sum == 25)
    
    let nothing = emptyNumbers.asSequence().foldr(0, { $0 + $1 })
    XCTAssertTrue(nothing == 0)
    
  }
