Determine if the JS environment has Symbol support. Supports spec, or shams.
没有声明运行依赖。
^0.17.0
^21.1.1
^0.2.0
^2.5.8
^5.6.5
^2.5.0
^2.6.12
^0.1.13
=8.8.0
^0.9.5
^2.0.1
^0.3.1
^10.3.2
^2.0.0
^5.9.0
next