code: function parseEmphasis(tokens) {
    const newTokens = [];
    let i = 0;
    while (i < tokens.length) {
      if (typeof tokens[i] === 'string') {
        if (tokens[i] !== '') {
          newTokens.push(tokens[i]);
        }
        i++;
      } else {
        const currTag = tokens[i].type;
        if (INLINE_OPEN.indexOf(currTag) !== -1) {
          const closeTag = getCloseTag(currTag);
          const closePos = getClosePos(tokens, i, closeTag, tokens[i].markup);
          if (closePos !== -1) {
            let intEmphasis = getOneEmphasis(tokens, i, closePos);
            if (Array.isArray(intEmphasis) && intEmphasis.length === 0) {
              intEmphasis = '';
            }
            if (currTag === 'link_open') {
              newTokens.push(getUrlToken({ tokens, intEmphasis, num: i }));
            } else {
              newTokens.push(getEmphasisToken({ tokens, intEmphasis, currTag, num: i }));
            }
            i = closePos + 1;
            continue;
          }
        }
        newTokens.push(tokens[i]);
        i++;
      }
    }
    return newTokens;
  }
docs: parseEmphasis - Function parse inline and extract emphasis-tokens
  
  @param tokens
  @returns {Array}