code: def delete_site(self, site_name, replacement_site=None):
          
          site = self.find_by_name(site_name, self.sites)
          if not site:
              return False
          self.sites.remove(site)
          if site.location:
              site.location.sites.remove(site)
          samples = site.samples
          for samp in samples:
              samp.site = ''
          del site
          return samples
docs: Remove site with name site_name from self.sites.
          If the site belonged to a location, remove it from the location's site list.
          If the site had any samples, change sample.site to "".