code: function checkSpacingAroundFirstToken(node) {
              const firstToken = node && sourceCode.getFirstToken(node);
  
              if (firstToken && firstToken.type === "Keyword") {
                  checkSpacingAround(firstToken);
              }
          }
docs: Reports the first token of a given node if the first token is a keyword
  and usage of spacing around the token is invalid.
  
  @param {ASTNode|null} node - A node to report.
  @returns {void}