  We review the condensation completion of a modular tensor category, which
yields a fusion 2-category of codimension-1 and higher defects in a $2+1$D
topological order. We apply the condensation completion to $2+1$D toric code
model and a $\mathbbm Z_4$ chiral topological order. In both cases, we
explicitly enumerate the $1$d and $0$d defects present in these topological
orders, along with their fusion rules. We also talk about other applications of
condensation completion: alternative interpretations of condensation completion
of a braided fusion category; condensation completion of the category of
symmetry charges and its correspondence to gapped phases with symmetry; for a
topological order $\cC$, one can also find all gapped boundaries of the
stacking of $\cC$ with its time-reversal conjugate through computing the
condensation completion of $\cC$.
