def device_capability_types
      # Capabilities are appended to the bos header
      ptr = pointer + offset_of(:dev_capability)
      bNumDeviceCaps.times.map do
        cap = DeviceCapability.new self, ptr.read_pointer
        ptr += FFI.type_size(:pointer)
        Call::BosTypes.find cap.bDevCapabilityType
      end
    end
def device_capability_types
      # Capabilities are appended to the bos header
      ptr = pointer + offset_of(:dev_capability)
      bNumDeviceCaps.times.map do
        cap = DeviceCapability.new self, ptr.read_pointer
        ptr += FFI.type_size(:pointer)
        Call::BosTypes.find cap.bDevCapabilityType
      end
    end
@return [Array<Symbol>]  Types of Capabilities

 @see Call::BosTypes