rest-assured/src/main/java/io/restassured/builder/ResponseSpecBuilder.java
public ResponseSpecBuilder expectHeader(String headerName, String expectedValue) {
        spec.header(headerName, expectedValue);
        return this;
    }
public ResponseSpecBuilder expectHeader(String headerName, String expectedValue) {
        spec.header(headerName, expectedValue);
        return this;
    }
Expect that a response header matches the supplied name and value.

@param headerName    The name of the expected header
@param expectedValue The value of the expected header
@return The builder