What is the test for determining whether a statutory provision has crossed the line demarking laws of general application from other enactments?

I have underlined some words and phrases in the passage to show that where it is alleged that a statutory provision has crossed the line demarking laws of general application from other enactments, that must be demonstrated by evidence. Of course, evidence about the motives of individual members of the legislature or even about the more abstract "intention of the legislature" or "legislative purpose of the enactment" is not relevant. What is relevant is evidence about the effect of the legislation. In fact, evidence about its "application". From that evidence the legislative policy can be inferred. But evidence that the effect bears harder or more frequently on Indians than on non-Indians is not enough. The evidence must go further than that. It must show that the law impairs the status or capacity of a particular group of Indians. This is the significant passage from Kruger v. R. at p. 110: If the law does extend uniformly throughout the jurisdiction the intention and effects of the enactment need to be considered. The law must not be "in relation to" one class of citizens in object and purpose. But the fact that a law may have graver consequence to one person than to another does not, on that account alone, make the law other than one of general application. There are few laws which have a uniform impact. The line is crossed, however, when an enactment, though in relation to another matter, by its effect, impairs the status or capacity of a particular group. (The italics are Lambert J.A.'s.)