modules/spring-mock-mvc/src/main/java/io/restassured/module/mockmvc/RestAssuredMockMvc.java
public static MockMvcAuthenticationScheme principalWithCredentials(final Object principal, final Object credentials, final String... authorities) {
        return new MockMvcAuthenticationScheme() {
            public void authenticate(MockMvcRequestSpecification mockMvcRequestSpecification) {
                mockMvcRequestSpecification.auth().principalWithCredentials(principal, credentials, authorities);
            }
        };
    }
public static MockMvcAuthenticationScheme principalWithCredentials(final Object principal, final Object credentials, final String... authorities) {
        return new MockMvcAuthenticationScheme() {
            public void authenticate(MockMvcRequestSpecification mockMvcRequestSpecification) {
                mockMvcRequestSpecification.auth().principalWithCredentials(principal, credentials, authorities);
            }
        };
    }
Authenticate using the given principal and credentials. Used as:
<pre>
RestAssured.authentication = principalWithCredentials(myPrincipal, myCredentials);
</pre>
or in a {@link MockMvcRequestSpecBuilder}:
<pre>
MockMvcRequestSpecification req = new MockMvcRequestSpecBuilder().setAuth(principalWithCredentials(myPrincipal, myCredentials)). ..
</pre>

@param principal   The principal to use.
@param credentials The credentials to use
@param authorities Optional list of authorities
@return A {@link MockMvcAuthenticationScheme} instance.
@see MockMvcAuthenticationSpecification#principalWithCredentials(Object, Object, String...)