public byte[] byteArray(int minCapacity) {
        final byte[] byteArray = this.byteArray;
        if (byteArray.length >= minCapacity) {
            return byteArray;
        }
        return allocateByteArray(minCapacity);
    }
Returns a thread-local byte array whose length is equal to or greater than the specified
{@code minCapacity}.
core/src/main/java/com/linecorp/armeria/internal/common/util/TemporaryThreadLocals.java