Can you explain the Builder pattern with a real-world .NET example?

Builder separates complex object construction from its representation. For example, building

n HttpRequest with optional headers, query params, and body:

public class HttpRequestBuilder
{
private HttpRequestMessage _request = new HttpRequestMessage();
public HttpRequestBuilder SetMethod(HttpMethod method)
{
_request.Method = method;
return this;
}
public HttpRequestBuilder AddHeader(string key, string value)
{

_request.Headers.Add(key, value);

return this;
}
public HttpRequestMessage Build() => _request;
}

llows building requests step-by-step fluently.