NtlmHttpServletRequest request = new NtlmHttpServletRequest(mockRequest, null);

        // getRemoteUser() will throw NPE when trying to call getName() on null principal
        assertThrows(NullPointerException.class, () -> request.getRemoteUser());
        assertNull(request.getUserPrincipal());
        assertEquals("NTLM", request.getAuthType());
    }

    @Test

    Principal principal;

    NtlmHttpServletRequest(final HttpServletRequest req, final Principal principal) {
        super(req);
        this.principal = principal;
    }

    @Override
    public String getRemoteUser() {
        return this.principal.getName();
    }

    @Override
    public Principal getUserPrincipal() {
        return this.principal;
    }

    @Override
    public String getAuthType() {

        // Act: Call the method under test
        String actualUserName = ntlmRequest.getRemoteUser();

        // Assert: Verify that the returned user name is the expected one
        assertEquals(expectedUserName, actualUserName, "getRemoteUser should return the principal's name.");
    }

    /**
     * Test method for {@link NtlmHttpServletRequest#getUserPrincipal()}.

    Principal principal;

    NtlmHttpServletRequest(final HttpServletRequest req, final Principal principal) {
        super(req);
        this.principal = principal;
    }

    @Override
    public String getRemoteUser() {
        return principal.getName();
    }

    @Override
    public Principal getUserPrincipal() {
        return principal;
    }

    @Override
    public String getAuthType() {

            return null;
        }

        @Override
        public String getContextPath() {
            return null;
        }

        @Override
        public String getRemoteUser() {
            return null;
        }

        @Override
        public boolean isUserInRole(String role) {
            return false;
        }

        @Override

            return "";
        }

        @Override
        public String getQueryString() {
            return null;
        }

        @Override
        public String getRemoteUser() {
            return null;
        }

        @Override
        public boolean isUserInRole(String role) {
            return false;
        }

        @Override

            }

            @Override
            public String getQueryString() {
                return null;
            }

            @Override
            public String getRemoteUser() {
                return null;
            }

            @Override
            public boolean isUserInRole(String role) {
                return false;
            }

            @Override

        }

        @Override
        public String getQueryString() {
            throw new UnsupportedOperationException();
        }

        @Override
        public String getRemoteUser() {
            throw new UnsupportedOperationException();
        }

        @Override
        public boolean isUserInRole(String role) {
            throw new UnsupportedOperationException();
        }

            }

            @Override
            public String getQueryString() {
                return null;
            }

            @Override
            public String getRemoteUser() {
                return null;
            }

            @Override
            public boolean isUserInRole(String role) {
                return false;
            }

            @Override

            return "";
        }

        @Override
        public String getQueryString() {
            return null;
        }

        @Override
        public String getRemoteUser() {
            return null;
        }

        @Override
        public boolean isUserInRole(String role) {
            return false;
        }

        @Override