Analisis hukum persaingan usaha terhadap kewajiban pemberitahuan pengambilalihan saham perusahaan kepada komisi pengawas persaingan usaha: studi kasus putusan komisi pengawas persaingan usaha Nomor 09/KPPU- M/ 2012 = Competition law analysis of acquisition notification duty to business competition supervisory comission: case study of the decision of business competition supervisory comission Number 09/ KPPU-M 2012