public final H2AsyncClientBuilder setDefaultCredentialsProvider(final CredentialsProvider credentialsProvider) {
        this.credentialsProvider = credentialsProvider;
        return this;
    }
Sets default {@link CredentialsProvider} instance which will be used
for request execution if not explicitly set in the client execution
context.

@return this instance.
httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/H2AsyncClientBuilder.java