@Test
    public void testNullHeaderName() {
        val matcher = new HeaderMatcher();
        TestsHelper.expectException(() -> matcher.matches(new CallContext(MockWebContext.create(), new MockSessionStore())),
            TechnicalException.class, "headerName cannot be blank");
    }
Tests {@link HeaderMatcher}.

@author Jerome Leleu
@since 1.9.3
pac4j-core/src/test/java/org/pac4j/core/matching/matcher/HeaderMatcherTests.java