Analisis terhadap pelaksanaan upah minimum yang memenuhi asas kepastian dan keadilan hukum: studi putusan Mahkamah Agung Republik Indonesia nomor 847k/Pdt.Sus-PHI/2017 = Analysis of minimum wage implementation fulfilling principle of certainty of law and law of justice review of supreme stipulation number 847k/Pdt.Sus-PHI/2017