Presumption that Amending Acts have some purpose

There is a general presumption that amendments are carried out for some purpose and every statute has an object. The same is state as follows.[Blogger]
"However, when current and prior versions of a  statute are at issue, there is a presumption that the  General Assembly, in amending a statute, intended to effect  a substantive change in the law." 
[Virginia-American Water  Co. v. Prince William County Serv. Auth., 246 Va. 509, 517,  436 S.E.2d 618, 622-23 (1993); Dale v. City of Newport  News, 243 Va. 48, 51, 412 S.E.2d 701, 702 (1992).]
 "Further,  we assume that the General Assembly's amendments to a  statute are purposeful, rather than unnecessary. 
[AAA  Disposal Servs. v. Eckert, 267 Va. 442, 446, 593 S.E.2d  260, 263 (2004); Virginia-American Water Co., 246 Va. at  517, 436 S.E.2d at 623; Cape Henry Towers, Inc. v. National  Gypsum Co., 229 Va. 596, 600, 331 S.E.2d 476, 479 (1985)."
 West Lewinsville Heights Citizens Association et. al v. Board of Supervisors of Fairfax County, 270 Va. 259, 618 S.E.2d. 311 (2005).