MatchPattern: &matcher.StringMatcher_Exact{
			Exact: exact,
		},
	}
}

// StringMatcherWithPrefix creates a string matcher for v with the extra prefix inserted to the
// created string matcher, note the prefix is ignored if v is wildcard ("*").
// The wildcard "*" will be generated as ".+" instead of ".*".
func StringMatcherWithPrefix(v, prefix string) *matcher.StringMatcher {
	switch {

				MatchPattern: &matcher.StringMatcher_Exact{
					Exact: "abc-exact",
				},
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			actual := StringMatcherWithPrefix(tc.v, tc.prefix)
			if !cmp.Equal(actual, tc.want, protocmp.Transform()) {
				t.Errorf("want %s but got %s", tc.want.String(), actual.String())
			}
		})
	}
}

func TestStringMatcherRegex(t *testing.T) {

	return nil, fmt.Errorf("unimplemented")
}

func (srcPrincipalGenerator) principal(key, value string, _ bool, useAuthenticated bool) (*rbacpb.Principal, error) {
	m := matcher.StringMatcherWithPrefix(value, spiffe.URIPrefix)
	return principalAuthenticated(m, useAuthenticated), nil
}

type requestPrincipalGenerator struct{}