docs: public TypeInformation<?>[] getParameterTypes(Class<?>[] signature) {
  		final TypeInformation<?>[] types = new TypeInformation<?>[signature.length];
  		for (int i = 0; i < signature.length; i++) {
  			try {
  				types[i] = TypeExtractor.getForClass(signature[i]);
  			} catch (InvalidTypesException e) {
  				throw new ValidationException(
  					"Parameter types of scalar function " + this.getClass().getCanonicalName() +
  					" cannot be automatically determined. Please provide type information manually.");
  			}
  		}
  		return types;
  	}