FROZEN             67 src/interface.h     static Interface value_interface(VALUE + FROZEN);  // Cached.
FROZEN             72 src/interface.h     static Interface value_interface(VALUE + CONST + FROZEN);  // Cached.
FROZEN            120 src/interface.h     if (*ok) Chase()->flags_ |= FROZEN;
FROZEN            139 src/interface.h   bool IsFrozen() { return Chase()->flags_ & FROZEN; }