Type guard. Prefer this over instanceof PilatesError for cross-realm
safety — when two copies of the library are loaded in the same process
(pnpm hoisting), instanceof fails on instances created by the other
copy because they have different .prototype identities. The Symbol.for
tag is shared across copies.
Type guard. Prefer this over
instanceof PilatesErrorfor cross-realm safety — when two copies of the library are loaded in the same process (pnpm hoisting),instanceoffails on instances created by the other copy because they have different.prototypeidentities. The Symbol.for tag is shared across copies.