code: protected void init(ConfigurationValueProvider[] configurationValueProviders) {
          Object containerValue = null;
  
          for (ConfigurationValueProvider container : configurationValueProviders) {
              containerValue = container.getValue(namespace, name);
              for (String alias : aliases) {
                  if (containerValue != null) {
                      break;
                  }
                  containerValue = container.getValue(namespace, alias);
              }
          }
  
          if (containerValue == null) {
              value = defaultValue;
          } else {
              try {
                  value = valueOf(containerValue);
                  wasOverridden = true;
              } catch (NumberFormatException e) {
                  throw new UnexpectedLiquibaseException("Error parsing "+containerValue+" as a "+type.getSimpleName());
              }
          }
      }
docs: Initialize this property with values in the given ConfigurationProvers. If the configurationValueProviders do not contain
  a default value, the property is initialized with the value set by {@link #setDefaultValue(Object)}.
  If multiple configurationValueProviders contain values, the first in the list wins.