Remove untrue tip about zero-length arrays.

in any Activity where you read and write the file, you need an object to use as the intrinsic

lock for the synchronized statements:</p>

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<p><strong>Interesting Fact:</strong></p>

<p>A zero-length array is lighter-weight than a normal Object, so it's great for an

intrinsic lock.</p>

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<pre>

// Object for intrinsic lock

static final Object[] sDataLock = new Object[0];