config/src/main/java/org/springframework/security/config/annotation/web/configurers/HeadersConfigurer.java
public HeadersConfigurer<H> addHeaderWriter(HeaderWriter headerWriter) {
		Assert.notNull(headerWriter, "headerWriter cannot be null");
		this.headerWriters.add(headerWriter);
		return this;
	}
public HeadersConfigurer<H> addHeaderWriter(HeaderWriter headerWriter) {
		Assert.notNull(headerWriter, "headerWriter cannot be null");
		this.headerWriters.add(headerWriter);
		return this;
	}
Adds a {@link HeaderWriter} instance

@param headerWriter the {@link HeaderWriter} instance to add
@return the {@link HeadersConfigurer} for additional customizations