Headphones On, Screen Dark, Somebody Behind You: A Four-Cell Interruptibility Register, Nineteen Weeks on One Open-Plan Floor, and the Shoulder-Tap Rule It Now EnforcesResolving to Headphones On, Screen Dark, Somebody Behind You: A Four-Cell Interruptibility Register, Nineteen Weeks on One Open-Plan Floor, and the Shoulder-Tap Rule It Now Enforces…