<prompt> Translate the following text to EnglishWakati Uholanzi walipoanza tena kuangazia Java na Moluccas katika karne ya 18, Bugis walitumia fursa hiyo kwa kuvamia Perak na Kedah, na kuwaweka wakuu wao Selangor na kuwa nguvu nyuma ya kiti cha enzi katika Johor.  <response>: With the Dutch concentrating once more on Java and the Moluccas in the 18th century, the Bugis took advantage of the vacuum by raiding Perak and Kedah, imposing their chieftains in Selangor and becoming the power behind the throne in Johor. 