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'use strict';
/** * Convert a string or array into a projection object, retaining all * `-` and `+` paths. */
module.exports = function parseProjection(v, retainMinusPaths) {  const type = typeof v;
  if (type === 'string') {    v = v.split(/\s+/);  }  if (!Array.isArray(v) && Object.prototype.toString.call(v) !== '[object Arguments]') {    return v;  }
  const len = v.length;  const ret = {};  for (let i = 0; i < len; ++i) {    let field = v[i];    if (!field) {      continue;    }    const include = '-' == field[0] ? 0 : 1;    if (!retainMinusPaths && include === 0) {      field = field.substring(1);    }    ret[field] = include;  }
  return ret;};