<!--
  Note: if the issue is about documentation or the website, please file it at:
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**Do you want to request a *feature* or report a *bug*?** Bug, I guess

**What is the current behavior?** 


```
  console.error node_modules/fbjs/lib/warning.js:33
    Warning: Detected multiple renderers concurrently rendering the same context provider. This is currently unsupported.
```

Steps to reproduce the behavior:
1. `git clone https://github.com/stereobooster/react-context-issue`
2. `cd react-context-issue`
3. `yarn`
4. `yarn test`

**What is the expected behavior?** no warning

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?** React 16.4. Browser not affected, because error is in node.js

Open this because of https://github.com/facebook/react/pull/13127#issuecomment-402527012

Issue happens because of Enzyme (https://github.com/airbnb/enzyme/issues/1693), code is unreleased, so I copy-pasted it from master. 

I'm looking for advice or some clue on how to fix this, so I would be able to create PR in Enzyme repo (or in React repo if this is the case). Thank you.


type: 'div',
                  nodeType: 'host',
                  props: {},
                  instance: null,
                  rendered: ['Three'],
                },
              },
            ],
          },
          {
            type: 'div',
            nodeType: 'host',
            props: {},
            instance: null,
            rendered: ['Four'],
          },
        ],
      }),
    );
  });
  it('toTree() handles complicated tree of fragments', () => {
    const renderer = ReactTestRenderer.create(
      <React.Fragment>
        <React.Fragment>
          <div>One</div>
          <div>Two</div>
          <React.Fragment>
            <div>Three</div>
          </React.Fragment>
        </React.Fragment>