code: function ensureScalar(value) {
    if (isUndefined(value) || value === null) {
      return value;
    }
    var length = 1;
    var description = 'a scalar';
    if (value.type === vectorProto.type) {
      length = value.size();
      value = value.values[0];
      description = 'a vector';
    } else if (Array.isArray(value)) {
      length = value.length;
      value = value[0];
      description = 'an array';
    }
    if (length !== 1) {
      throw new Error('expected a single scalar value but got ' +
        description + ' of length ' + length);
    }
    return value;
  }
docs: If value is a vector or array, this function will return the single scalar value contained or throw an error if the length is not 1. If value isn't a vector or array, it is simply returned.