1*ac2a7c1bSSadaf Ebrahimi[ 2*ac2a7c1bSSadaf Ebrahimi? explicit key1 : explicit value, 3*ac2a7c1bSSadaf Ebrahimi? explicit key2 : , # Explicit empty 4*ac2a7c1bSSadaf Ebrahimi? explicit key3, # Implicit empty 5*ac2a7c1bSSadaf Ebrahimisimple key1 : explicit value, 6*ac2a7c1bSSadaf Ebrahimisimple key2 : , # Explicit empty 7*ac2a7c1bSSadaf Ebrahimi] 8