### Question:
PsuIdHeaderInterceptor implements Interceptor { @Override public Request.Builder preHandle(Request.Builder builder) { if (QUOTES.equals(builder.headers().get(RequestHeaders.PSU_ID))) { builder.headers().replace(RequestHeaders.PSU_ID, null); } return builder; }  @Override Request.Builder preHandle(Request.Builder builder);  }### Answer:
@Test void apply_withValidPsuId() { builder.header(RequestHeaders.PSU_ID, PSU_ID); interceptor.preHandle(builder); assertEquals(PSU_ID, builder.headers().get(RequestHeaders.PSU_ID)); }
@Test void apply_psuIdQuotes() { builder.header(RequestHeaders.PSU_ID, QUOTES); interceptor.preHandle(builder); assertNull(builder.headers().get(RequestHeaders.PSU_ID)); }
@Test void apply_noPsuIdHeader() { builder.header(RANDOM_HEADER, RANDOM_HEADER); interceptor.preHandle(builder); assertFalse(builder.headers().containsKey(RequestHeaders.PSU_ID)); assertEquals(builder.headers(), builder.headers()); }