nginx custom error pages

location = /error_pages/404.html {
	internal;
	root /var/www/html;
}

location = /error_pages/502.html {
	internal;
	root /var/www/html;
}

location / { 
	proxy_pass........
	error_page 404 = /error_pages/404.html;
	error_page 502 = /error_pages/502.html;
}