copies: document how 'copies' dict instances are reused
We avoid copying these instances as much as we can, so it's not
obvious what's safe to do with them. This patch tries to explain what
is safe and what is not.
Differential Revision: https://phab.mercurial-scm.org/D6578
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}