How to use the @aws-cdk/cfnspec.schema function in @aws-cdk/cfnspec

function _diffProperty(oldV: any, newV: any, key: string, resourceSpec?: cfnspec.schema.ResourceType) {
    let changeImpact = types.ResourceImpact.NO_CHANGE;

    const spec = resourceSpec && resourceSpec.Properties && resourceSpec.Properties[key];
    if (spec && !deepEqual(oldV, newV)) {
      switch (spec.UpdateType) {
        case cfnspec.schema.UpdateType.Immutable:
          changeImpact = types.ResourceImpact.WILL_REPLACE;
          break;
        case cfnspec.schema.UpdateType.Conditional:
          changeImpact = types.ResourceImpact.MAY_REPLACE;
          break;
        default:
          // In those cases, whatever is the current value is what we should keep
          changeImpact = types.ResourceImpact.WILL_UPDATE;
      }
    }

    return new types.PropertyDifference(oldV, newV, { changeImpact });
  }

private readResourceChange(resourceChange: ResourceChange) {
    switch (resourceChange.scrutinyType) {
      case cfnspec.schema.ResourceScrutinyType.IdentityPolicyResource:
        // AWS::IAM::Policy
        this.statements.addOld(...this.readIdentityPolicyResource(resourceChange.oldProperties));
        this.statements.addNew(...this.readIdentityPolicyResource(resourceChange.newProperties));
        break;
      case cfnspec.schema.ResourceScrutinyType.ResourcePolicyResource:
        // AWS::*::{Bucket,Queue,Topic}Policy
        this.statements.addOld(...this.readResourcePolicyResource(resourceChange.oldProperties));
        this.statements.addNew(...this.readResourcePolicyResource(resourceChange.newProperties));
        break;
      case cfnspec.schema.ResourceScrutinyType.LambdaPermission:
        this.statements.addOld(...this.readLambdaStatements(resourceChange.oldProperties));
        this.statements.addNew(...this.readLambdaStatements(resourceChange.newProperties));
        break;
    }
  }

}

/**
 * Changes to IAM statements
 */
export class IamChanges {
  public static IamPropertyScrutinies = [
    cfnspec.schema.PropertyScrutinyType.InlineIdentityPolicies,
    cfnspec.schema.PropertyScrutinyType.InlineResourcePolicy,
    cfnspec.schema.PropertyScrutinyType.ManagedPolicies,
  ];

  public static IamResourceScrutinies = [
    cfnspec.schema.ResourceScrutinyType.ResourcePolicyResource,
    cfnspec.schema.ResourceScrutinyType.IdentityPolicyResource,
    cfnspec.schema.ResourceScrutinyType.LambdaPermission,
  ];

  public readonly statements = new DiffableCollection();
  public readonly managedPolicies = new DiffableCollection();

  constructor(props: IamChangesProps) {
    for (const propertyChange of props.propertyChanges) {
      this.readPropertyChange(propertyChange);
    }
    for (const resourceChange of props.resourceChanges) {
      this.readResourceChange(resourceChange);
    }

    this.statements.calculateDiff();
    this.managedPolicies.calculateDiff();
  }

this.metadata = args.metadata || new DifferenceCollection({});
    this.outputs = args.outputs || new DifferenceCollection({});
    this.parameters = args.parameters || new DifferenceCollection({});
    this.resources = args.resources || new DifferenceCollection({});
    this.unknown = args.unknown || new DifferenceCollection({});

    this.iamChanges = new IamChanges({
      propertyChanges: this.scrutinizablePropertyChanges(IamChanges.IamPropertyScrutinies),
      resourceChanges: this.scrutinizableResourceChanges(IamChanges.IamResourceScrutinies),
    });

    this.securityGroupChanges = new SecurityGroupChanges({
      egressRulePropertyChanges: this.scrutinizablePropertyChanges([cfnspec.schema.PropertyScrutinyType.EgressRules]),
      ingressRulePropertyChanges: this.scrutinizablePropertyChanges([cfnspec.schema.PropertyScrutinyType.IngressRules]),
      egressRuleResourceChanges: this.scrutinizableResourceChanges([cfnspec.schema.ResourceScrutinyType.EgressRuleResource]),
      ingressRuleResourceChanges: this.scrutinizableResourceChanges([cfnspec.schema.ResourceScrutinyType.IngressRuleResource]),
    });
  }

this.conditions = args.conditions || new DifferenceCollection({});
    this.mappings = args.mappings || new DifferenceCollection({});
    this.metadata = args.metadata || new DifferenceCollection({});
    this.outputs = args.outputs || new DifferenceCollection({});
    this.parameters = args.parameters || new DifferenceCollection({});
    this.resources = args.resources || new DifferenceCollection({});
    this.unknown = args.unknown || new DifferenceCollection({});

    this.iamChanges = new IamChanges({
      propertyChanges: this.scrutinizablePropertyChanges(IamChanges.IamPropertyScrutinies),
      resourceChanges: this.scrutinizableResourceChanges(IamChanges.IamResourceScrutinies),
    });

    this.securityGroupChanges = new SecurityGroupChanges({
      egressRulePropertyChanges: this.scrutinizablePropertyChanges([cfnspec.schema.PropertyScrutinyType.EgressRules]),
      ingressRulePropertyChanges: this.scrutinizablePropertyChanges([cfnspec.schema.PropertyScrutinyType.IngressRules]),
      egressRuleResourceChanges: this.scrutinizableResourceChanges([cfnspec.schema.ResourceScrutinyType.EgressRuleResource]),
      ingressRuleResourceChanges: this.scrutinizableResourceChanges([cfnspec.schema.ResourceScrutinyType.IngressRuleResource]),
    });
  }