What is the common law tort of abuse of process?

"'The common law tort of abuse of process arises when one uses the court's process for a purpose other than that for which the process was designed.' (Rusheen v. Cohen [(2006)] 37 Cal.4th [1048,] 1056.) 'To succeed in an action for abuse of process, a litigant must establish that the defendant (1) contemplated an ulterior motive in using the process, and (2) committed a willful act in the use of the process not proper in the regular conduct of the proceedings.' (Id. at p. 1057.)" (JSJ Limited Partnership v. Mehrban (2012) 205 Cal.App.4th 1512, 1522.)