public Builder host(String host) {
            if (StringUtils.hasText(host)) {
                this.subjectContext.setHost(host);
            }
            return this;
        }
Ensures the {@code Subject} being built will reflect the specified host name or IP as its originating
location.

@param host the host name or IP address to use as the {@code Subject}'s originating location.
@return this {@code Builder} instance for method chaining.
core/src/main/java/org/apache/shiro/subject/Subject.java