code: private static String validateAlias(final String alias) {
  		NullArgumentException.validateNotNull(alias, "Alias");
  		if (!alias.startsWith("/")) {
  			throw new IllegalArgumentException(
  					"Alias does not start with slash (/)");
  		}
  		// "/" must be allowed
  		if (alias.length() > 1 && alias.endsWith("/")) {
  			throw new IllegalArgumentException("Alias ends with slash (/)");
  		}
  		return alias;
  	}
docs: Validates that aan alias conforms to OSGi specs requirements. See OSGi R4
  Http Service specs for details about alias validation.
  
  @param alias to validate
  @return received alias if validation succeeds
  @throws IllegalArgumentException if validation fails