SourceFunction Scala

[Ankur Sharma]

Hello,

I am trying to use a custom source function (declaration given below) for 
DataStream.
if I add the source to stream using add source: 

val stream = env.addSource(new QueryOneSource(args))
I get following error:  Any explanations and help ??

Error:(14, 31) could not find implicit value for evidence parameter of type 
org.apache.flink.api.common.typeinfo.TypeInformation[org.mpi.debs.Tuple]
    val stream = env.addSource(new QueryOneSource(args))
                              ^
Error:(14, 31) not enough arguments for method addSource: (implicit 
evidence$15: scala.reflect.ClassTag[org.mpi.debs.Tuple], implicit evidence$16: 
org.apache.flink.api.common.typeinfo.TypeInformation[org.mpi.debs.Tuple])org.apache.flink.streaming.api.scala.DataStream[org.mpi.debs.Tuple].
Unspecified value parameter evidence$16.
    val stream = env.addSource(new QueryOneSource(args))
                              ^

class QueryOneSource(filenames: Array[String]) extends SourceFunction[Tuple] {
val nextTuple: Tuple // case class Tuple(id: Long, value: Int)
override def run(ctx: SourceContext[Tuple]) = {
  while (true) {
    nextRecord()
    ctx.collect(this.nextTuple)
  }
}

override def cancel() = { }
}

override def nextRecord() = {
}
}

Best,
Ankur Sharma
Information Systems Group
3.15 E1.1 Universität des Saarlandes
66123, Saarbrücken Germany
Email: ankur.sha...@mpi-inf.mpg.de <mailto:ankur.sha...@mpi-inf.mpg.de> 
            an...@stud.uni-saarland.de <mailto:an...@stud.uni-saarland.de>

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