'use strict';
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const { PassThrough } = require('stream');
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module.exports = function (/*streams...*/) {
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var sources = []
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var output = new PassThrough({objectMode: true})
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output.setMaxListeners(0)
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output.add = add
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output.isEmpty = isEmpty
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output.on('unpipe', remove)
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Array.prototype.slice.call(arguments).forEach(add)
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return output
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function add (source) {
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if (Array.isArray(source)) {
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source.forEach(add)
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return this
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}
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sources.push(source);
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source.once('end', remove.bind(null, source))
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source.once('error', output.emit.bind(output, 'error'))
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source.pipe(output, {end: false})
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return this
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}
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function isEmpty () {
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return sources.length == 0;
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}
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function remove (source) {
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sources = sources.filter(function (it) { return it !== source })
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if (!sources.length && output.readable) { output.end() }
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}
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}
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