Lots of WATING tread "OkHttp Connection" created automatically

Lots of WATING tread "OkHttp Connection" created automatically.
I do lots of call to getOrderHistory and there is no way to avoid this large number of calls to getOrderHistory method of kiteconnect.

I wonder who creates these threads and why they are in WAIT state. My application runs but it gives outOfMemory error due to excess of WAITING threads.
Question:
(a)Who creates these many threads? (I am not creating these). I bet it is created by any of the kiteconnect method
Is there anyway to kill /avoid creation of these many threads.

ERROR:
Exception in thread “Sell” java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:717)
at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:957)
at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1378)
at okhttp3.ConnectionPool.put(ConnectionPool.java:153)
at okhttp3.OkHttpClient$1.put(OkHttpClient.java:166)
at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:265)
at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:134)
at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:113)
at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:125)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:200)
at okhttp3.RealCall.execute(RealCall.java:77)
at com.zerodhatech.kiteconnect.kitehttp.KiteRequestHandler.getRequest(KiteRequestHandler.java:51)
at com.zerodhatech.kiteconnect.KiteConnect.getOrderHistory(KiteConnect.java:386)
at BuyStocks.Sell(BuyStocks.java:945)
at ThreadController.run(ThreadController.java:151)
at java.lang.Thread.run(Thread.java:748)