Explain clearly the importance of barrier in multi-threaded OpenMP codes. Write two fragments of code using OpenMP directives that illustrate the use of implicit barriers. When is it safe to remove an implicit barrier? How is an implicit barrier removed in OpenMP? Explain clearly the importance of barrier in multi-threaded OpenMP codes. Write two fragments of code using OpenMP directives that illustrate the use of implicit barriers. When is it safe to remove an implicit barrier? How is an implicit barrier removed in OpenMP