How to use the plywood.ApplyExpression function in plywood

public toExpression(expression: Expression, name: string, nestingLevel: number): ApplyExpression {
    const relativeNesting = this.relativeNesting(nestingLevel);
    const formulaName = `__formula_${name}`;
    if (relativeNesting < 0) throw new Error(`wrong nesting level: ${relativeNesting}`);
    return new ApplyExpression({
      name,
      operand: new ApplyExpression({ expression, name: formulaName }),
      expression: $(formulaName).divide($(formulaName, relativeNesting)).fallback(0)
    });
  }

toExpression(expression: Expression, name: string, _nestingLevel: number): ApplyExpression {
    return new ApplyExpression({
      name,
      expression: this.calculate(expression)
    });
  }
}

protected applyExpression(quantileExpression: PlywoodExpression, name: string, nestingLevel: number): ApplyExpression {
    if (!(quantileExpression instanceof QuantileExpression)) throw new Error(`Expected QuantileExpression, got ${quantileExpression}`);
    const expression = new QuantileExpression({ ...quantileExpression.valueOf(), value: this.definition.percentile / 100 });
    return new ApplyExpression({ name, expression });
  }
}

protected applyExpression(expression: Expression, name: string, nestingLevel: number): ApplyExpression {
    return new ApplyExpression({ expression, name });
  }
}

public toExpression(expression: Expression, name: string, nestingLevel: number): ApplyExpression {
    const relativeNesting = this.relativeNesting(nestingLevel);
    const formulaName = `__formula_${name}`;
    if (relativeNesting < 0) throw new Error(`wrong nesting level: ${relativeNesting}`);
    return new ApplyExpression({
      name,
      operand: new ApplyExpression({ expression, name: formulaName }),
      expression: $(formulaName).divide($(formulaName, relativeNesting)).fallback(0)
    });
  }