The municipality of metropolitan Seattle is a municipal corporation as authorized by chapter 35.58 RCW and defined in RCW 35.58.020(1). The municipality of metropolitan Seattle has established procedures for adopting its own resolutions, rules, and regulations, in accordance with RCW 35.58.130. RCW 35.58.273, however, requires the municipality to "adhere to the provisions of the Administrative Procedure Act," chapter 34.04 RCW, in adopting one particular rule. This chapter was created to fulfill that legal requirement.