 
 
 public protocol _UTF8Decoder : UnicodeDecoder {
-  func _parseNonASCII() -> (valid: Bool, length: UInt8)
+  func _parseNonASCII() -> (isValid: Bool, length: UInt8)
   var buffer: Buffer { get set }
 }
 

      
    buffer._bitCount = buffer._bitCount &- bitsConsumed

    guard _fastPath(valid) else {
      return .invalid(length: Int(length))
    }
    return .valid(encodedScalar)
  }
}


  }
  
  public // @testable
  func _parseNonASCII() -> (isValid: Bool, length: UInt8) {
    _sanityCheck(buffer._storage & 0x80 != 0) // this case handled elsewhere
    if buffer._storage                & 0b0__1110_0000__1100_0000
                                     == 0b0__1100_0000__1000_0000 {
