text: export function array(maybeArray) {
    if (Array.isArray(maybeArray)) {
      return maybeArray;
    }
    throw new Error('Expected array');
  }
  
  export function number(maybeNumber) {
    if (typeof maybeNumber === 'number') {
      return maybeNumber;
    }
    throw new Error('Expected number'); // TODO: add "got" message
  }
  
  export function object(maybeObject) {
    if (maybeObject && typeof maybeObject === 'object') {
      return maybeObject;
    }
    throw new Error('Expected object');
  }
  
  export function string(maybeString) {
    if (typeof maybeString === 'string') {
      return maybeString;
    }
    throw new Error('Expected string');
  }
  