### Question:
PeerId implements Copiable<PeerId>, Serializable, Checksum { public boolean parse(final String s) { if (StringUtils.isEmpty(s)) { return false; } final String[] tmps = StringUtils.splitPreserveAllTokens(s, ':'); if (tmps.length < 2 || tmps.length > 4) { return false; } try { final int port = Integer.parseInt(tmps[1]); this.endpoint = new Endpoint(tmps[0], port); switch (tmps.length) { case 3: this.idx = Integer.parseInt(tmps[2]); break; case 4: if (tmps[2].equals("")) { this.idx = 0; } else { this.idx = Integer.parseInt(tmps[2]); } this.priority = Integer.parseInt(tmps[3]); break; default: break; } this.str = null; return true; } catch (final Exception e) { LOG.error("Parse peer from string failed: {}.", s, e); return false; } } PeerId();  PeerId(final Endpoint endpoint, final int idx);  PeerId(final String ip, final int port);  PeerId(final String ip, final int port, final int idx);  PeerId(final Endpoint endpoint, final int idx, final int priority);  PeerId(final String ip, final int port, final int idx, final int priority); @Override long checksum(); static PeerId emptyPeer(); @Override PeerId copy(); static PeerId parsePeer(final String s); Endpoint getEndpoint(); String getIp(); int getPort(); int getIdx(); int getPriority(); void setPriority(int priority); boolean isEmpty(); @Override String toString(); boolean parse(final String s); boolean isPriorityNotElected(); boolean isPriorityDisabled(); @Override int hashCode(); @Override boolean equals(final Object obj); static final PeerId ANY_PEER; }### Answer:
@Test public void testToStringParseFailed() { final PeerId pp = new PeerId(); final String str1 = ""; final String str2 = "192.168.1.1"; final String str3 = "92.168.1.1:8081::1:2"; assertFalse(pp.parse(str1)); assertFalse(pp.parse(str2)); }